due to losses during the battle of scimitar hill and wastage during august 1915, the 2nd mounted division had to be reorganised. on 4 september 1915, the 2nd composite mounted brigade was formed from the 3rd (notts and derby) and 4th (london) mounted brigades. the brigade formed a battalion sized unit 3rd nottinghamshire and derbyshire regiment. the brigade embarked for mudros on 2 november and returned to egypt in december 1915 where it was reformed and remounted.