Private Andrew Millar
The background and military record of this North Irish Horseman are not clear. He is listed in the Presbyterian Church in Ireland's Roll of Honour as Trooper Andrew Millar from Ballyboley, worshipping in the Ballynure Congregation, Carrickfergus Presbytery. His name is included on the Roll of Honour of the Ballynure Presbyterian Church.
According to Richard Wallace in his The World War One Rolls of Honour in Ballynure Presbyterian Church and Ballynure Methodist Church, Millar was born in Ballyboley, Ballynure, County Antrim, he was gassed in 1917, and his sister also served during the war, in the Queen Mary Army Auxiliary Corps.
One possibility is that he was the Andrew Millar born at Ballycarry, Larne, on 9 September 1875, one of ten children of spirit merchant William Millar and his wife Jane (Jennie) (née Thompson). His sister Jane Hill Millar and a Joseph Millar (a brother?) were living at Ballyboley at the time of the 1911 Census and the 1912 Ulster Covenant.
Millar does not appear to have served overseas with the North Irish Horse. It is possible that he transferred to another regiment at some point during the war, which could explain the reference to him being gassed.
Image sourced from Richard Wallace's work on the Ballynure Rolls of Honour (see above).