Complex sentence: The 2/1st West Somerset Yeomanry was formed in September 1914,they were converted into a cyclist unit in 1916 they remained in the United Kingdom until moving to Ireland in May 1918, until the end of the war.
Split into simpler sentences: The 2/1st West Somerset Yeomanry was formed in September 1914 and converted into a cyclist unit in 1916. It remained in the United Kingdom until moving to Ireland in May 1918, until the end of the war.