With the portion of the walls between the Gate of St. Romanus and the Gate of Charisius, memorable historical events are associated which cannot be passed over without some notice, however brief. On account of its central position in the line of the land fortifications, this part of the walls was named the Mesoteichion (Μεσοτείχιον).[364] It was also known as the Myriandrion,[365] on account of its proximity to the Gate of Polyandrion; the portion to the south of the Lycus being further distinguished as the Murus Bacchatareus,[366] after the Tower Baccaturea near the Gate of St. Romanus.[367] [Illustration: View Across the Valley of the Lycus (Looking North).] Owing to the configuration of the ground traversed by the Mesoteichion, it was at this point that a besieging army generally delivered the chief attack. Here stood the gates opening upon the streets which commanded the hills of the city; here was the weakest part of the fortifications, the channel of the Lycus rendering a deep moat impossible, while the dip in the line of walls, as they descended and ascended the slopes of the valley, put the defenders below the level occupied by the besiegers. Here, then, for Constantinople was the “Valley of Decision”—here, in the armour of the city, the “heel of Achilles.” In the siege of 626 by the Avars, the first siege which the Theodosian Walls sustained, the principal attack was made from twelve towers which the enemy built before the fortifications extending from the Gate of Charisius to the Gate of the Pempton, and thence to the Gate of St. Romanus.[368] Upon the Gate of Charisius attempts were made: by Justinian II. and his allies for the recovery of his throne in 705;[369] by Alexius Branas against Isaac Angelus in 1185;[370] by John Cantacuzene in 1345[371] and through it the Comneni entered in 1081, by bribing the German guards (Nemitzi) at the gate, and wrested the sceptre from the hand of Nicephorus Botoniates.[372] In 1206, during the struggle in which the Latins, soon after their capture of the city, involved themselves with Joannicus, King of Bulgaria, a raid was made upon the Gate of St. Romanus and the adjacent quarter by Bulgarian troops encamped near the capital.[373] In 1328 the gate was opened to admit Andronicus III. by two partisans, who stupefied the guards with drink, and then assisted a company of his soldiers to scale the walls with rope ladders.[374] In 1379 John VI. Palæologus and his son Manuel, after effecting their escape from the prison of Anemas, and making terms with Sultan Bajazet, entered the city by this gate, and obliged Andronicus IV. to retire from the throne he had usurped.[375]