If this be so, then the name Harbour of Eleutherius was its earlier designation, and the port itself was the oldest on the side of the city towards the Sea of Marmora, its construction being ascribed to a certain Eleutherius, who was present at the foundation of Constantinople.[1115] Its antiquity is supported by the aspect of its remains, for the walls enclosing it on the north are the oldest portion of the fortifications of the city, and possibly belong to the time of Constantine the Great. Here the statue of Eleutherius was erected, in the appropriate equipment of an excavator, with a spade in his hand and a basket on his back.[1116] [Illustration: Tower Guarding the Harbour of Eleutherius and Theodosius.[1117]] From the fact that the harbour was called Portus Theodosianus, it is evident that it was improved by Theodosius I., to whom the city owed so many public works. When precisely the harbour was filled in is a question not easily settled. The Anonymus declares, indeed, that this was done in the reign of Theodosius I., with the earth excavated in laying the foundations of the column of that emperor in the Forum of Taurus.[1118] But, had that been the case, the _Notitia_ would scarcely have mentioned an abandoned harbour among the objects for which the Twelfth Region of the city was remarkable. What is certain is that the harbour was destroyed some time before the eleventh century; probably because the earth brought by the stream of the Lycus, which flows into the harbour, and the sand cast up by the sea, proved too troublesome for the maintenance of a sufficient depth of water. The harbour measured 786 yards from east to west and 218 yards from south to north. Along its southern side, as well as along a portion of its side towards the east, it was protected by a mole twelve feet thick, carefully constructed of masonry, and extending from the Gate of St. Æmilianus (Daoud Pasha Kapoussi) eastwards for about 436 yards, and then northwards for 327 yards more.[1119] Upon the greater portion of the mole, walls were constructed for the military defence of the harbour. The entrance was at the north-eastern end, between the head of the mole and the site of the Gate Yeni Kapou, the opening through which the Roumelian Railway now runs, and was guarded by a tower built at a short distance out in the sea.[1120] [Illustration: Portion of the Wall Around the Harbour of Eleutherius and Theodosius.[1121]]