[3] During the Second Boer War he was present at the battles of Ladysmith (October 1899), Colenso (December 1899), Spion Kop (January 1900) and Vaal Krantz (February 1900).

For his service in the war he was promoted a brevet lieutenant colonel on 29 November 1900, and was appointed a Companion of the Order of the Bath (CB) in the South Africa honours list published on 26 June 1902.

[7] However, his horror at the creation of concentration camps in South Africa and ill-treatment of Boer civilians by the British military led to him writing anonymous articles which were published in the Freeman's Journal, which brought attention to the matters.

From 1917 on, he was a member of Sinn Féin, which led to his Dublin home being raided a number of times by the authorities during the Irish War of Independence.

[1] As a result, when Smuts was in London for the 1921 Imperial Conference, he detoured to Dublin, met Éamon de Valera, and assisted both sides in brokering the Truce of July 1921 that ended the Irish War of Independence.

[13] Moore and Jennie Wyse Power were the only two senators to oppose the election of Lord Glenavy as Cathaoirleach as he had been a former prominent Unionist.

He was a vocal critic of the Boundary Agreement which was made between Ireland and the United Kingdom in 1925 and this persuaded him to join Clann Éireann which had been founded by Professor William Magennis.

[18] He was nominated as a candidate for Leas-Chathaoirleach (vice-chairman) of the Seanad in 1928 but was defeated by Senator Patrick W. Kenny of Cumann na nGaedheal by twenty-seven votes to twenty-one.

His son, Ulick Moore, served with the Sixth Battalion, Connaught Rangers during World War I, and was killed in action at Sainte-Emilie on 22 March 1918.