The 5th Indian Division began to arrive in Sudan in early September 1940. The 29th Indian Infantry Brigade were placed on the Red Sea coast to protect Port Sudan, the 9th Indian Infantry Brigade was based south-west of Kassala and the 10th Indian Infantry Brigade (William Slim) were sent to Gedaref, with the divisional headquarters, to block an Italian attack on Khartoum from Goz Regeb to Gallabat, on a front of . Gazelle Force (Colonel Frank Messervy) was formed on 16 October, as a mobile unit to raid Italian territory and delay an Italian advance.