Isthmus of Corinth
Neck of land, 5,857 m wide at its narrowest point, joining the Peloponnesos to the mainland of Greece. Neolithic and Bronze Age pottery discovered in several places there shows early occupation of the area. East of it an inscribed stele marked the boundary between Corinth and Megara. Mythology tells of a dispute between Poseidon and Helios for possession of the land; Briareos, who was appointed arbitrator, decided in favor of Poseidon.
The Isthmus formed a bridge for land traffic and a barrier to E-W shipping, and attempts were made early to facilitate passage from sea to sea. In the 6th c. B.C. a causeway (diolkos), 3.60-4.20 m wide, was constructed, the pavement of which has been exposed for a distance of nearly 1 km near the Corinthian Gulf. On it ships were hauled on cradles, as shown by deep wheel ruts, 1.50 m apart. The diolkos was still in use in the 9th c. A.D.
Plans to dig a canal were conceived by Periander, Demetrios Poliorketes, Julius Caesar, Caligula, Nero, and Herodes Atticus. Nero broke ground for a canal during his visit to Greece in A.D. 67. Two of his trenches, 2,000 and 1,500 m long but nowhere reaching water level, and several pits, 37-42 m deep, were clearly visible before the modern canal was dug in 1881-93. Traces of Nero's work still remain.
To protect themselves and the Peloponnesos from attacks by land, the Corinthians fortified the Isthmus. The earliest of the walls, which dates back to about 1200 B.C., may have been planned to stem the recurrent waves of “Dorian” invaders at the end of the Mycenaean period. It was probably left unfinished when the decisive invasion took place. The next line of defense, built in haste in 480 B.C. against an expected Persian attack that never materialized, has left no sure traces. There are extensive remains of a later fortification, built probably in 279 B.C., when the Gauls, who overran the N of Greece, threatened invasion of the Peloponnesos. This wall crossed the Isthmus so far to the W as to leave the Precinct of Poseidon (see Isthmia) and large parts of Corinthian territory open to the attackers. There are also references to a wall built in the reign of Valerian (A.D. 253-60). The “Wall of Justinian,” which can be followed through most of its course, had originally 153 towers on the N side, spaced at intervals of about 40 m. Near the E end, close to the Sanctuary of Poseidon, there is a massive fortress whose walls abut against the trans-Isthmus wall. The fortress and much of the Isthmus wall are constructed largely out of reused material from the sanctuary. Recent excavations (1967-69) tend to show that these walls are earlier than Justinian; if this is correct, they must have been rebuilt during his reign. The fortress has three gates: the NE Gate, incorporating an earlier Roman gateway; the S Gate, built or repaired by Justinian's engineer Victorinus; and a smaller gate in the W wall. Repairs were again made in the reign of Manuel II (1391-1425). Until the fall of Constantinople in 1453, the trans-Isthmus wall and the fortress remained a bulwark against invasions from the N.
BIBLIOGRAPHYJ. H. Jenkins & H. Megaw in BSA 32 (1931-32) 68-89PI; H. N. Fowler, Corinth I: Topography (1932) 46-71MPI; N. M. Verdelis in AthMitt 71 (1956) 51-59PI; 73 (1958) 140-45I; A. Philippson-E. Kirsten, GL III, Part I: Der Peloponnes (1959); O. Broneer in Antiquity 32 (1958) 80-88MI; id., Atti del Settimo Congr. Intern. di Archeologia Class. I (1961) 243-49MI; id., Hesperia 35 (1966) 346-62MPI; 37 (1968) 25-35MPI; J. R. Wiseman in Hesperia 32 (1963) 248-75MPI; B. v. Freyberg, Erlanger Geologische Abhandlungen, Heft 95, Geologie des Isthmus von Korinth (1973). See also Isthmia, with
Bibliography. O. BRONEER