Trans-Isthmian Walls in the Age of Justinian Hohlfelder, Robert L Greek, Roman and Byzantine Studies; Summer 1977; 18, 2; Periodicals Archive Online pg. 173

Trans-Isthmian Walls in the 
Age of Justinian 
Robert L. H ohlfelder 

I N De Aedificiis 4.2.27-28,1 Procopius speaks in detail of the implemen­
tation of Justinian's defense plan for central Greece in the 550's, 
conceived and enacted in response to deteriorating conditions in 

the Balkans.2 Justinian restored the defenses at Thermopylae and the 
fortifications of walled cities, such as Athens, above the Isthmus.3 

Realizing the vulnerability of the unwalled cities of the Peloponnesus 
and the time required to fortify each separately, the emperor decided 
to block access to southern Greece by fortifying the Isthmus itself with 
a wall. In this regard, Procopius states that this decision was necessary 
because "a great extent of the old wall had already collapsed there." 

This restored wall, long known as the Hexamilion or Justinian's 
Wall, can be seen in ruins at several locations throughout Corinthia. 
It has been correctly associated with Aed. 4.2.27-28 and has received 
considerable mention in modern accounts.4 The earlier trans-Isthmian 
wall has not. 

At BP 2.4.11,5 Procopius implies that this 'old wall' was in existence 

1 In the text of H. B. Dewing (LCL 1940) the passage runs as follows: TaOTa 
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£/L&.v8av£v dvat, AOYLCa/L£VOC on 3~ ot 7ToAvc T£Tp{.p£Tat xp6voc, "l KaT<l /Lt(ic £7Tl/L£Ao 'iTO , TOV 

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2 Ernst Stein, Histoire du Bas-Empire II (Paris 1949) 305-10; Dimitri Obolensky, The 

By!?:antine Commonwealth (London 1971) 42ff. 
3 Justinian's efforts at Thermopylae proved effective against the Bulgars during the in­

vasion of A.D. 559 (see infra n.26) but did not deter the Avaro-Slavic incursions at the end of 
the century (see infra). Justinian also renewed the walls of Corinth within the Isthmus 
fortifications at this time (Aed. 4.2.24). 

4 R. J. H. Jenkins and H. Megaw, "Researches at Isthmia," BSA 32 (1931-32) 68-89, particu­
larly pp.78-79 "the trans-Isthmian wall ... is the work of Justinian"; H. N. Fowler, Corinth 
I: Introduction, Topography, Architecture (Princeton 1932) 55; for references to the various 
trans-Isthmian walls, see Paul A. Clement, "The Date of the Hexamilion," Studies in 
Memory of Basil Laourdas (Thessaloniki 1975) 159 n.1. 

5 OVTW T£ cx£30v a7TavTac MEAA'I)vaC 7TA~v II£Ao7ToYV'I)cLwv 3uPyaca/L€VOL a7T£XcVp'l)WV (ed. 
Dewing). 

173 



174 TRANS-ISTHMIAN WALLS IN THE AGE OF JUSTINIAN 

earlier in Justinian's reign. Following his accession, the emperor, whose 
primary concerns were drawn simultaneously to the east and west 
but not to the north, paid too little attention to the volatile Danubian 
region and its weakened defenses. The price paid for this neglect and 
the denuding of the frontier for other military theaters was paid in 
A.D. 540 when Kutrigur Bulgars swept into the Balkans. They attacked 
Illyricum, plundered Thessaly, captured Cassandreia (ancient Poti­
daea), whose fall according to Procopius (Aed. 4.3.22) marked the first 
time these barbarians had taken a walled city, ravaged the Thracian 
Chersonesus, and even reached the fortifications of Constantinople. 
The defenses at Thermopylae, which had saved much of central 
Greece from the Getae in A.D. 517,6 proved to be no obstacle to this 
new incursion and were surmounted (BP 2.4.10), probably by use of 
the same path employed by Xerxes in the fifth century B.C. (Hdt. 
7.216-18).7 Apparently the Bulgarian penetration stalled in Corinthia. 
The implication in this passage of Procopius, if not the explicit state­
ment, is that the fortifications of the Isthmus, the keystone of which 
would have been a trans-Isthmian wall, had held. 

While it is safe to deduce the existence of a trans-Isthmian wall in 
A.D. 540, it is equally possible to say that this defensive system had not 
been constructed by Justinian in the first ye_ars of his reign in response 
to earlier penetrations of the Balkan peninsula by the Antes, the 
Sclavini and the <Huns' (Bulgars).s Procopius' failure to assign the wall 
specifically to the emperor, given the panegyric dimension of De 
Aedificiis, is a convincing argumentum ex silentio.9 It is most unlikely that 
he would have missed the opportunity to comment on imperial fore­
sight in constructing a fortification that helped save the Peloponnesus 
from the ravages of the Bulgars.1o But if the wall was standing in 540 
but was not built by Justinian, when was it constructed? 

a The 'Getae', mentioned in Marcellinus Comes, s.a. 517, have been associated with the 
'Antae' mentioned in Procop. BG 3.14.2 and Anec. IS.20 by Stein, op.cit. (supra n.2) 105-06. 
(All references to Marcellinus Comes in this paper are to his Chronicon, Mommsen, Chronica 
Minora II). A. A. Vasiliev, Justin the First (Cambridge [Mass.] 1950) 308, suggests that the 
Getae probably were Slavs. 

7 I follow here H. B. Dewing (LeL) ad Procop. BP 2.4.10. 
S Procop. Anec. 18.20. 
tOn Aed. as panegyric see G. Downey, 'Procopius on Antioch: A Study of Method in the 

De aedificiis," By{antion 14 (1939) 361-78. 
10 At the very least, one would expect some account of repairs to the wall following the 

great earthquake of A.D. 522, which according to Procopius destroyed the circuit wall of 
Corinth (Aed. 4.2.24 and Anec. 18.42). Robert L. Scranton, Corinth XVI: Mediaeval Architecture 



ROBERT L. HOHLFELDER 175 

Recent excavations conducted at Isthmia by Paul A. Clement have 
provided interesting data which offer a solution to this question.l1 

Professor Clement excavated two graves in 1967, dug next to the so­
called ]ustinianic Wall near the Northeast Gate. Only three of the 
eight coins found in these excavations were datable, the latest being 
an issue of Marcian.12 Since archaeological evidence suggests that the 
wall was already in existence when the graves were dug, these coins 
eliminate the possibility of its construction in the sixth century. In 
commenting on these finds, Clement stated that "This is a puzzle, for 
it is anomalous to find evidence for the abandoning of a stairway [to a 
fighting platform of the trans-Isthmian wall] almost a century before 
supposedly it was built."13 The anomaly disappears if one accepts the 
wall as the earlier one mentioned in Aed. 4.2.27-28. 

Also in 1967, Professor Clement cleared the roadway through the 
Northeast Gate with meticulous care, cleaning out the joints, clamp­
cuttings and dowel holes of the re-used stones which formed the 
pavement blocks. a His excavations produced 18 coins, the latest of 
which he assigned to Arcadius or Honorius. At least one of these coins, 
however, and perhaps another as well seems to be of a later date in 
the fifth century, probably from the reign of Theodosius Ip5 In a 
subsequent campaign in 1969, one other pertinent numismatic datum 
was uncovered: clearing operations on the roadway through the 
Northeast Gate produced one coin of Leo 1.16 

This numismatic evidence from Isthmia suggests that the earlier 
wall of Aed. 4.2.27-28 was constructed sometime in the middle of the 
fifth century, probably late in the reign of Theodosius II. Two other 
dates for its construction, however, have been offered. In an early 
interpretation of the new evidence, Oscar Broneer suggested that the 

(Princeton 1957) 8, states without further comment that the trans-Isthmian wall was re­
conditioned after this catastrophe. If there is any archaeological evidence for restoration, 
perhaps, given Procopius' silence, we have here testimony to local repairs of fortifications 
as mandated by imperial edict (Cod.Theod. 15.1.34). 

11 Paul A. Clement, "Isthmia," ArchDeit 23 (1968) Chronika, 137-43; "Isthmia Excava­
tions," ArchDeit 25 (1970) Chronika, 161-67; "Isthmia Excavations," ArchDelt 26 (1971) 
Chronika, 100-11 ; and op.cit. (supra n.4) 159-64. 

12 Clement, op.cit. (supra n.4) 163-64. He does not identify the monogram type. 
13 Clement, op.cit. 1968 (supra n.ll) 140. 
H Clement, op.cit. (supra n.4) 160-63. 
15 ibid. Clement's coin 17, with a facing bust and an anepigraphic reverse featuring a cross 

as type, seems later than the first decade of the fifth century; so too his no.15. 
16 Clement, op.cit. (supra n.4) 163. 



176 TRANS-ISTHMIAN \VALLS IN THE AGE OF JUSTINIAN 

wall might date to the late fourth centuryP This assignment seems 
unlikely, since Zosimus (5.6) reports that Alaric moved easily through 
Corinthia. The Zosimus account might permit another interpretation, 
namely that any trans-Isthmian defenses in existence-possibly dating 
back to the reign of Valerian (Zos. 1.29)-were simply insufficiently 
manned at the time of Alaric's attack.Is Clement's suggestion, how­
ever, of a slightly later date for the wall, the early years of the fifth 
century but posterior to the fall of Rome to Alaric in A.D. 410, seems 
more probable.I9 

While Professor Clement is quite right in linking the fifth-century 
fortification of the Isthmus to the traumatic years following the fall of 
Rome, his association of the trans-Isthmian wall and the building of 
the land fortifications of Constantinople (A.D. 413) as "a reaction to 

Alaric's sack of Rome" seems less secure.20 The Isthmia coin finds 
point to a later date in the fifth century when the fear of Attila would 
have been more immediate and compelling than the memory of 
Alaric. For A.D. 422 Marcellinus Comes (s.a. 422) tersely comments: 
Hunni Thraciam vastaverunt. This incursion was simply a prelude to the 
more savage attacks that began in the decade of the 440's. In 441/2 and 
again in 447 Attila was at war with the Roman Empire with the 
Balkans as the major battlefield.21 One Hunnic foray even reached as 
far south as Thermopylae in 447.22 It was during these times of un­
certainty and under the cloud of Attila that the walls of Thessalonica 
were constructed.23 It seems equally probable that the building of the 

17 Broneer follows the early date offered by Clement, op.cit. 1968 (supra n.11) 139-40: see 
Oscar Broneer, Isthmia II: Topography and Architecture (Princeton 1973) 2 n.5. 

18 20s. 1.29 (Bonn ed. p.254): ~V86VTOC 8~ airr(jJ r£poVTtov TOV • IcOp.ov 8w{3iivaL, '7TaVTa AOL'7TOV 
1Jv aVT(jJ 8lxa '7T()VOV Kat p.a)(TJC MWcLp.a, TWV '7T()'\£WV 8L1); TiJv Cr.ClpaA£LaV 7}v 0 'IcOp.oc '7TapELXEv 

, ...,' , ~ aVTaLC aT£LXLCTWV ovcwv. 
18 Clement, op.cit. (supra n.4) 163. 
20 ibid. J. B. Bury, Selected Essays (Cambridge 1930) 234-35, noted that Anthemius planned 

the new walls of Constantinople "for the Hunnic war which he foresaw." 
21 See J. Otto Maenchen-Helfen, The World of the Huns: Studies in Their History and Culture 

(Berkeley 1973) 108ff; also E. A. Thompson, A History of Attila and the Huns (Oxford 1948) 
78ft'. 

22 Marcellinus Comes, s.a. 447: Attila rex usque ad Thermopolim infestus advenit. The sugges­
tion of David J. Blackman in H. Schlager, D. J. Blackman and J. Schafer, "Der Hafen von 
Anthedon mit Beitragen zur Topographie und Geschichte der Stadt," AA 83 (1968) 92 
n.120, that this Thermopylae was nearer the Danube must be rejected. 

23 Michael Vickers employs epigraphical evidence as his primary source to date the forti­
fications of Thessalonica to ca 448 and links their construction to the threat of the Huns. 
See "The Late Roman Walls ofThessalonika," Roman Frontier Studies 1969, ed. E. Birley et al. 



ROBERT L. HOHLFELDER 177 

trans-Isthmian wall can be understood best in this historical context. 
It may well represent another major defensive project executed late 
in the reign of Theodosius II after the engagement at Thermopylae 
and motivated by the fear of further Hunnic onslaughts against 
central Greece. 

As the threat of the Huns subsided in the late fifth century, the wall 
may have fallen into disrepair or may have been maintained through 
local efforts as required by imperial law (Cod. Theod. 15.1.34). But what­
ever its condition, it was adequate to meet the exigency of A.D. 540. 
Shortly after this date, however, it can be assumed that the fortifica­
tions were damaged severely, most likely by an earthquake. The 
earthquake of 551, which Procopius mentions in another context as 
particularly destructive to central Greece (BG 4.25.16--23), is the most 
likely candidate.24 Moreover, archaeological evidence from the exca­
vations at Corinth offers testimony to the destructiveness of a tectonic 
disturbance at about the same time.25 It seems that the earlier wall 
may have been sufficiently destroyed in the earthquake of 551, or 
another one in the same period but not reported in our literary 
sources, to necessitate extensive rehabilitation by Justinian. 

Procopius notes that time was a consideration for Justinian in de­
ciding his plans for the defense of this region of Greece, allowing the 
interpretation that the rebuilding of the wall was undertaken with a 
sense of urgency provoked by the continuing unsettled conditions 
along the Danubian frontier and the possibility of renewed Bulgar 
attacks.26 Certainly the restoration was carried out quickly and was 
completed by the end of the decade of the 550's at the latest.27 

(Cardiff 1974) 253-54, and his other studies there cited. Brian Croke, in his unpublished 
Oxford dissertation The Chronicle of MarceIlinus in its Contemporary and Historiographical 
Context, suggests an earlier date ca 442/3, associating the construction of the walls directly 
with the removal of the Prefecture of Illyricum from Sirmium in 441 and before the great 
Hunnic invasion of 447. 

24 Also Evagrius, Hist.Eccl. 4.23 (ed. Bidez, p.171). 
2S Scranton, op.cit. (supra n.l0) 8, and James Wiseman, "Excavations in Corinth, The 

Gymnasium Area, 1967-1968," Hesperia 38 (1969) 87. 
26 In A.D. 559 another Bulgarian attack penetrated Greece to Thermopylae, where the 

defenses held (Agathias 5.23, Bonn ed. p.330). See Obolensky, op.cit. (supra n.2) 45. The 
restoration of the trans-Isthmian wall probably had just been completed at the time of 
this incursion by Zabergan and his Kutrigurs. 

27 Either the traditional date for the publication of Aed., 558--60, or the revised date, 
553-55, would place its appearance after the earthquake of 551 and provide a terminus ante 
quem for the reconstruction of the trans-Isthmian wall in the decade of the 550'5 but after 
551. See J. A. S. Evans, "The Dates of the Anecdota and the De Aedificiis of Procopius," CP 



178 TRANS-ISTHMIAN WALLS IN THE AGE OF JUSTINIAN 

Materials from various ruined structures including pagan shrines 
were employed in the repairs and reconstruction in accordance with 
long-standing official policy.28 Such was the ultimate fate of the 
Temple of Poseidon and the Theater of Isthmia.29 

The restored trans-Isthmian wall with its many fortresses (cf>povpLa) 
and towers (cf>v>..aKrrJpLa) was one of several important Justinianic con­
structions in Greece.30 By itself, it provides sufficient evidence to belie 
as erroneous slander the charge in Anecdota 26.33 that no public 
construction was undertaken in all of Greece by Justinian.3! It was 
this trans-Isthmian wall which survived in some state of preservation 
with possible restorations by Theodore, despot of Mistra, in the late 
fourteenth century to serve Manuel II in 1415 as the wall of the 
Theodosian age had served Justinian.32 

Procopius ends Aed. 4.2.28 by claiming that the restored wall would 
protect the Peloponnesus from attack even if the defenses at Thermop­
ylae were forced. Events in subsequent decades around 580, when the 
first raids of A vars and Slavs reached central Greece, would prove the 
fallacy of his judgement.33 Although neither literary nor archaeo-

64 (1969) 29-30 (A.D. 558 or earlier), and G. Downey, "The Composition of Procopius, De 
Aedifidis," TAPA 78 (1947) 171-83 (559/560). Stein, op.dt. (supra n.2) 837, argues for a date 
earlier in the decade between 553-55. Stein's dating is accepted by B. Rubin, Das Zeitalter 
Justinians (Berlin 1960) 174-75. John H. Finley's dating of Aed. to A.D. 550 is unlikely: 
"Corinth in the Middle Ages," SpeCltlum 7 (1932) 478 n.4. 

B8 Cod.Theod. 15.1.36 and 16.10.25. 
It Oscar Broneer, Isthmia I: Temple of Poseidon (Princeton 1971) 2, and Elizabeth R. 

Gebhard, The Theater at Isthmia (Chicago 1973) 135. The Temple of Poseidon appears to have 
been first damaged during the attack of Alaric in 396. It was then used as a source of con­
struction materials in the following decades until its ultimate destruction in the age of 
Justinian. Ann E. Beaton and Paul A. Clement, "The Date of the Destruction of the 
Sanctuary of Poseidon on the Isthmus of Corinth," Hesperia 45 (1976) 267-79. 

30 Megaw, op.cit. (supra n.4) 69, quoting Phrantzes (Bonn ed. p.l08) on repairs of the 
Hexamilion in the reign of Manuel II, A.D. 1415, states that the wall consisted of a series of 
fortresses and 153 towers which Megaw assumes represents the configuration of the 

. Justinianic wall. Phrantzes (Bonn ed. p.96) offers a romantic and idealized vision of the age 
of Justinian in saying that JlJ.stinian, as emperor of almost the entire world. fortified the 
Isthmus OUK inr(P &I'&YK17c aAAa ,,61'01' ~4>&vrJ «XVrcp KaA61'. 

31 Another important construction during the age of Justinian was the harbor complex at 
Anthedon: see Blackman, op.cit. (supra n.22), who also cites other fortifications built in 
Greece by Justinian. Also Lloyd W. Daly. "Echinos and Justinian's Fortifications in Greece," 
AJA 46 (1942) 500-08. 

31 William Miller, Essays on the Latin Orient (Cambridge 1921) 98ff. 
33 The literature on this topic is formidable. For an introductory bibliography see Robert 

L. Hohlfelder, "Migratory Peoples' Incursions into Central Greece in the Late Sixth 
Century: New Evidence from Kenchreai," Actes du XIV· Congres international des Etudes 



ROBERT L. HOHLFELDER 179 

logical evidenc~ exists to indicate how Justinian's trans-Isthmian wall 
was breached or bypassed, it most certainly was. The excavations at 
Isthmia, Corinth, Nemea, Kenchreai and perhaps Phlius have pro­
duced incontrovertible archaeological proof of massive destruction at 
about this time.34 The Avars and the Slavs demonstrated again that a 
trans-Isthmian wall was never an ultimate defense. The same lesson 
had been taught earlier by the Dorians at the end of the Bronze Age; 
it would be confirmed once more by Murad in the fifteenth century.35 

CENTER FOR BYZANTINE STUDIES, DUMBARTON OAKS 

and the UNIVERSITY OF COLORADO 

April,1977 

byzantines, III (Bucharest 1976) 334 n.5, and Denis A. Zakythinos, 'R f3u'aVTtvT] 'E>J..ac 
(Athens 1965) 50 n.!. For an introduction to the problems involved in the coming of the 
Slavs and Avars to Greece, one should begin with the collected writings of Peter Charanis 
on this subject now available in the Variorum Reprints, Studies on the Demography of the 
Byzantine Empire (London 1972), and Vladislav Popovic, "Les temoins archeologiques des 
invasions avaro-slaves dans rIIlyricum byzantin," MelRome 87 (1975) 445-504. 

at I plan to present this evidence in detail in my study "The End of the Roman Empire 
in Central Greece: A Numismatic Perspective," to be published in vol. III, Aufstieg und 
Niedergang der romischen Welt. 

3S Oscar Broneer, "The Cyclopean Wall on the Isthmus of Corinth and its Bearing on Late 
Bronze Age Chronology," Hesperia 35 (1966) 346-62, and "The Cyclopean Wall on the 
Isthmus of Corinth, Addendum," Hesperia 37 (1968) 23-35; for the last Turkish assault on the 
Hexamilion, see the account in Miller, op.cit. (supra n.32). 

I thank the Trustees of Harvard University for the award of a visiting fellowship at 
Dumbarton Oaks 1976-77. I thank also Professor Dimitri Obolensky and Mr Brian Croke 
for their valuable criticisms and suggestions.