Complex sentence: After putting the division through intensive training, it left under Irish command of which each man took personal pride, with the 47th and 48th Brigade in the trenches behind Abbeyville by Christmas 1915, the 49th Brigade reaching the Western Front in February 1916.
Split into simpler sentences: After putting the division through intensive training, it left under Irish command of which each man took personal pride. The 47th and 48th Brigade were in the trenches behind Abbeyville by Christmas 1915, the 49th Brigade reaching the Western Front in February 1916.