Ulster Unionist peer Lord Rogan has become the first Northern Ireland politician to serve as deputy speaker in either House of Parliament.
Lord Rogan, formerly UUP president, said he was "deeply humbled" by the appointment.
Thursday marked his first day in the role and he sat on the 'woolsack' in the House of Lords for the first time.
"I view this appointment as a great honour and look forward to playing my part in helping facilitate the smooth running of the democratic process in the Mother of Parliaments," he said.
Ulster Unionist Party Leader Robin Swann said, “I have no doubt that his wisdom, common sense and forbearance will be an asset to the House of Lords in its daily business.”