By 12 December he was ready to attack. The Turks still held the Sanna-i-Yat positions on the left bank of the Tigris, but on the right they had been pushed back to a line running across the angle from the Tigris at Magasis towards its southern tributary the Shatt-el-Hai. The Turks under their German taskmasters had not been idle, and this angle, as well as the extension of the Turkish line along the Shatt-el-Hai and their secondary defences on the right bank of the Tigris above Kut, had been well protected by trenches and wire entanglements. The breaking down of these obstacles required stubborn fighting as well as skilful tactics, but the only alternative was to penetrate the Sanna-i-Yat positions and they had proved impregnable in the spring. A serious attempt had, however, to be made at Sanna-i-Yat in order to detain there a serious Turkish force; and while Marshall pushed his way through on the right bank, Cobbe was kept hammering on the left. On the 13th crossings of the Shatt-el-Hai were effected at Atab and Basrugiyeh some eight miles from Kut, and Marshall advanced on both banks to Kalah-Hadji-Fahan. On the 18th he reached a point on the Tigris just below Kut in the Khadairi bend. Rain and floods then impeded our advance for a month, but the Khadairi bend was gradually cleared of the Turks, and most of their positions in the angle of the Tigris and Shatt-el-Hai were taken. On 10 February Marshall pushed on beyond the Shatt-el-Hai, reached the right bank of the Tigris above the Shumran bend, and by the 16th forced the Turks in the Dahra bend across the river.