Peel County is a historic county in the Canadian province of Ontario. It was created in 1851 from a portion of York County. In 1973, Peel County became the Regional Municipality of Peel, as a result of the Ontario provincial government's regionalization of the rapidly developing counties surrounding Toronto. Named for Sir Robert Peel, Prime Minister of the United Kingdom, the county was organized in 1849. Settlers, however, were in Toronto Township as early as 1807. The Credit River was reserved for the Mississaugas, however they sold their land and moved to the Bruce Peninsula.