Informal grouping of four Prime Ministers in garden of #10 Downing Street during the Commonwealth Prime Ministers' Conference, London, England,. Photo includes John Diefenbaker of Canada, Field Marshall Mohammad Ayub Khan of Pakistan and Eric Louw of South Africa.

Prime Minister of the United Kingdom Harold Macmillan, Prime Minister of Australia Robert Menzies, and Prime Minister of the Federation of Rhodesian and Nyasaland, Sir Roy Welensky in garden of #10 Downing Street during ninth Commonwealth Prime Ministers' Conference, London, England.

"Empress of Canada" sliding out of dry dock at Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

"Empress of Canada" in dry dock prior to launching ceremonies at Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

"Empress of Canada" floating in river off of Vickers-Armstrongs shipyards following its launching, Newcastle-on-Tyne, England, 10 May, 1960.

Photo from above and from a distance of group of shipyard workers and their families behind a barricade awaiting the launching ceremonies of the "Empress of Canada", Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

Olive Diefenbaker (holding bouquet) and Mrs. Edna Cawthorne of Vickers facing the camera as they pose for a picture at the launching ceremony for the Empress of Canada, Newcastle on Tyne, 10 May, 1960.

Olive Diefenbaker holding bouquet and shaking hands with unidentified woman in crowd attending launching ceremony for Empress of Canada, Newcastle on Tyne, 10 May, 1960.

Olive Diefenbaker holding bouquet and shaking hands with unidentified woman in crowd attending launching ceremony for Empress of Canada, Newcastle on Tyne, 10 May, 1960.

Olive Diefenbaker on launching platform, pulling lever to christen the "Empress of Canada", Vickers-Armstrong Ltd. shipyards, Newcastle-on-Tyne, 10 May, 1960.

Olive Diefenbaker and Major General Sir Charles Dunphie (Chairman of Vickers-Armstrongs) leading official party's descent from launch platform, following launching of "Empress of Canada", Vickers-Armstrong Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

Edna Diefenbaker and unknown woman, In dress clothes, standing outside William and Mary Diefenbaker's Home, 117 Albert Street, Saskatoon.

Major General Sir Charles Dunphie (Chairman of Vickers-Armstrongs Ltd.) standing at head table of reception tea to reply to the toast to the ship builders during ceremonies following launching of the "Empress of Canada", Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

View of crowd at reception tea following launching of the "Empress of Canada", Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.

View of crowd at reception tea following launching of the "Empress of Canada", Vickers-Armstrongs Ltd. shipyards, Newcastle-on-Tyne, England, 10 May, 1960.