Passage: Queen Elizabeth II, in her address to Canada on Dominion Day in 1959, pointed out that the confederation of Canada on 1 July 1867 had been the birth of the "first independent country within the British Empire". She declared: "So, it also marks the beginning of that free association of independent states which is now known as the Commonwealth of Nations." As long ago as 1884 Lord Rosebery, while visiting Australia, had described the changing British Empire, as some of its colonies became more independent, as a "Commonwealth of Nations". Conferences of British and colonial prime ministers occurred periodically from the first one in 1887, leading to the creation of the Imperial Conferences in 1911.The Commonwealth developed from the imperial conferences. A specific proposal was presented by Jan Smuts in 1917 when he coined the term "the British Commonwealth of Nations" and envisioned the "future constitutional relations and readjustments in essence" at the Paris Peace Conference of 1919, attended by delegates from the Dominions as well as Britain. The term first received imperial statutory recognition in the Anglo-Irish Treaty of 1921, when the term British Commonwealth of Nations was substituted for British Empire in the wording of the oath taken by members of parliament of the Irish Free State.

Question: What was the changing British Empire called by Lord Rosebery?
Commonwealth of Nations