Empire forces held their lines of defence from Gaza to Beersheba. Both sides constructed extensive entrenchments, which were particularly strong where the trenches almost converged, at Gaza and Beersheba. In the centre of the line, the defences at Atawineh, at Sausage Ridge, at Hareira, and at Teiaha supported each other. They overlooked an almost flat plain, devoid of cover, making a frontal attack virtually impossible. The trench lines resembled those on the Western Front, except they were not so extensive, and they had an open flank. Both sides reorganised their armies in Palestine during the stalemate and appointed new commanders. The Yildirim Army Group (also known as Thunderbolt Army Group and Army Group F) was established in June, commanded by the German Empire General Erich von Falkenhayn. General Archibald Murray was sent back to England, replaced by Edmund Allenby in June to command the Egyptian Expeditionary Force. Allenby created two separate headquarters, one stayed in Cairo to administer Egypt, while his battle headquarters was established near Khan Yunis. He also reorganised the force into two infantry and one mounted corps. By 28 October 1917 the ration strength of the EEF fighting troops was 50,000. There were a further 70,000 unattested Egyptians. Raid on Ottoman railway The main line of communication south from Beersheba to Hafir el Aujah and Kossaima was attacked on 23 May 1917 when substantial sections of the railway line were demolished by Royal Engineers of the Anzac and Imperial Mounted Divisions. This raid was covered by the two mounted divisions including a demonstration towards Beersheba. Battle of Buqqar Ridge The occupation of Karm by the Allies on 22 October 1917 created a major point for supply and water for the troops in the immediate area. For the Ottoman forces, the establishment of a railway station at Karm placed the defensive positions known as the Hareira Redoubt and Rushdie System which formed a powerful bulwark against any Allied action under threat. To forestall this threat, General Erich von Falkenhayn, the Commander of the Yildirim Group, proposed a two phase attack. The plan called for a reconnaissance in force from Beersheba on 27 October, to be followed by an all out attack launched by the 8th Army from Hareira. This second phase was ironically scheduled to occur on the morning of 31 October 1917, the day when the Battle of Beersheba began. Southern Palestine Offensive Battle of Beersheba, 31