With the cessation of hostilities, Alexander was under serious consideration for appointment to the post of Chief of the Imperial General Staff, the British Army's most senior position beneath the sovereign. He was invited, though, by Canadian prime minister William Lyon Mackenzie King to be his recommendation to the King for the post of Governor General of Canada. Alexander thus chose to retire from the army and take up the new position, in anticipation of which he was on 26 January 1946 appointed Knight Grand Cross of the Order of Saint Michael and Saint George and created Viscount Alexander of Tunis, of Errigal in the County of Donegal, on 1 March. On 21 March 1946, the commission under the royal sign-manual and signet appointing Alexander was issued. Alexander was subsequently sworn-in during a ceremony in the Senate chamber on 12 April that year.