 From late April 1916 , after a German @-@ led Ottoman force attacked British yeomanry at Katia , British Empire forces in the region at first doubled from one brigade to two and then grew as rapidly as the developing infrastructure could support them . The construction of the railway and a water pipeline soon enabled an infantry division to join the light horse and mounted rifle brigades at Romani . During the heat of summer , regular mounted patrols and reconnaissance were carried out from their base at Romani , while the infantry constructed an extensive series of defensive redoubts . On 19 July , the advance of a large German , Austrian and Ottoman force across the northern Sinai was reported . From 20 July until the battle began , the Australian 1st and 2nd Light Horse Brigades took turns pushing out to clash with the advancing hostile column . 
