The authors of Canada's founding constitutional document — the British North America Act (amended as the Constitution Act, 1867) — spent many years debating the direction and concentration of political authority in Canada. Having settled on a federal system, the architects of Confederation distributed legislative power between a centralized national government and parallel provincial governments. The Constitution Act, 1867 enumerates the specific powers of Parliament and of the provincial legislatures, but provides somewhat less detail with regard to the executive bodies entrusted with administering those powers.
The description of "Executive Power" in the Constitution Act, 1867 begins by declaring Canada's relationship to the British monarchy: "The Executive Government and Authority of and over Canada is hereby declared to continue and be vested in the Queen." However, it is Parliament and the provincial legislatures — rather than the governor general and the lieutenant-governors as representatives of the Crown -- that give active expression to the political will of Canadians.
Accordingly, constitutional convention plays a vital role in the form and function of the executive branch of government and its central agencies. While the Constitution Act, 1867 grants the political executive an advisory role in relation to the Crown, in practice that advice is expressed in legislative instruments such as orders-in-council. The spirit of Canadian political culture — and indeed the progress of Canadian history itself — is illuminated by the records emanating from the executive and the centre of government in Canada.