In 1872 he attended a "General Meeting of the members and friends of the Irish Society for Women's Suffrage" in Blackrock, County Dublin.

Lord Monteagle was a cousin of Sir Cecil Spring Rice, British Ambassador to the United States from 1912 to 1918.

[6] The following year he became a Liberal Unionist out of a fear that Gladstone's 1886 Home Rule bill would lead to full independence for Ireland, and the dissolution of the United Kingdom.

He gradually became of the opinion that unionists had to recognise that in order to protect the Union, a compromising and workable agreement would need to be reached with Irish nationalists.

In 1917, he helped to arrange the Irish Convention, using his personal connections to ensure that the interests of Sinn Féin were represented after the party leadership refused to attend.

[15] His bill would have granted extensive home rule to a united Ireland, with responsibility over all domestic matters as a dominion within the empire.

[16] He caused indignation in the unionist community in Ireland when, in a February 1920 letter to The Times, he called for an end to the deportation and internment without trial of recently elected Sinn Féin politicians.