 Unionists in County Cork and Dublin were particularly influential.The initial leadership of the Ulster Unionist Party all came from outside what would later become Northern Ireland; men such as Colonel Saunderson, Viscount (later the Earl of) Midleton and the Dubliner Edward Carson, all members of the Irish Unionist Alliance.However, after the Irish Convention failed to reach an understanding on home rule and with the partition of Ireland under the Government of Ireland Act 1920, Irish unionism in effect split.