Complex sentence: The 2/1st served with the 2/2nd Mounted Division, and the original 1/1st initially served as dismounted infantry in Gallipoli, where it fought in the Battle of Scimitar Hill.
Split into simpler sentences: The 2/1st served with the 2/2nd Mounted Division. The original 1/1st initially served as dismounted infantry in Gallipoli, where it fought in the Battle of Scimitar Hill.