at rightangles eastwards following the line of the Gök River. That was an excellent defensive ground. For the Greeks, the question on whether to dig in and rest on their previous gains or to advance towards Ankara in great effort and destroy the Army of the Grand National Assembly. That was difficult to resolve and posed the eternal problems with which the Greek staff had to deal since the beginning of the war. The dangers of extending the lines of communications still further in such an inhospitable terrain that killed horses, caused vehicles to break down and prevented the movement of heavy artillery were obvious. The present front that gave the Greeks the control of the essential strategic railway was tactically most favourable, but the Army of the Grand National Assembly had escaped encirclement at Kütahya and so nothing had been settled. That made the temptation of achieving a knockout blow become irresistible. Battle On August 10, Greek King Constantine I finally committed his forces to an assault against the Sakarya Line. The Greeks marched hard for nine days before they made contact with the enemy. The march included an outflanking manoeuvre through the northern part of Anatolia through the Salt Desert, where food and water scarcely existed and so the advancing infantry foraged the poor Turkish villages for maize and water or meat from the flocks that were pastured on the fringe of the desert. On August 23, battle was finally joined by the Greeks making contact with the advanced Turkish positions south of the Gök River. The Turkish General Staff had made its headquarters at Polatlı, on the railway a few miles east of the coast of the Sakarya River, and its troops were prepared to resist. On August 26, the Greeks attacked all along the line. Crossing the shallow Gök, the infantry fought its way step up onto the heights, where every ridge and hill top had to be stormed against strong entrenchments and withering fire. By September 2, the commanding heights of the key Mount Chal were in Greek hands, but once the enveloping movement against the Turkish left flank had failed, the battle descended to a typical head-on confrontation of infantry, machine guns and artillery. The Greeks launched their main effort in the centre and pushed forward some 10 mi (16 km) in 10 days through the Turks' second line of defence. Some Greek units