Passage: Once constituted as a province, Ontario proceeded to assert its economic and legislative power. In 1872, the lawyer Oliver Mowat became Premier of Ontario and remained as premier until 1896. He fought for provincial rights, weakening the power of the federal government in provincial matters, usually through well-argued appeals to the Judicial Committee of the Privy Council. His battles with the federal government greatly decentralized Canada, giving the provinces far more power than John A. Macdonald had intended. He consolidated and expanded Ontario's educational and provincial institutions, created districts in Northern Ontario, and fought to ensure that those parts of Northwestern Ontario not historically part of Upper Canada (the vast areas north and west of the Lake Superior-Hudson Bay watershed, known as the District of Keewatin) would become part of Ontario, a victory embodied in the Canada (Ontario Boundary) Act, 1889. He also presided over the emergence of the province into the economic powerhouse of Canada. Mowat was the creator of what is often called Empire Ontario.

Question: When Oliver Mowat did battle with the federal government to decentralize Canada, what prominent figure did his efforts surpass in desired allocation of power?
John A. Macdonald