Michael Ancram, the former Conservative MP for Devizes, has taken his seat in the House of Lords.
He has been given a life peerage as Lord Kerr of Monteviot. He stood down as MP for the Wiltshire town before the General Election in May.
Lord Kerr, 65, served as an MP for 26 years. He had been MP for Devizes since 1992.
A hereditary peer as the 13th Marquess of Lothian, he was chairman of the Conservative Party from 1998 to 2001.
His new title is based on his surname, which is Kerr. He is known as Michael Ancram because he was previously known by his courtesy title the Earl of Ancram.