Holland River in the context of "Newmarket, Ontario"

York was a town and the second capital of the colony of Upper Canada. It is the predecessor to the old city of Toronto (1834–1998). It was established in 1793 by Lieutenant-Governor John Graves Simcoe as a "temporary" location for the capital of Upper Canada, while he made plans to build a capital near today's London, Ontario. Simcoe renamed the location York after Prince Frederick, Duke of York and Albany, George III's second son. Simcoe gave up his plan to build a capital at London, and York became the permanent capital of Upper Canada on February 1, 1796. That year Simcoe returned to Britain and was temporarily replaced by Peter Russell.

The original townsite was a compact ten blocks near the mouth of the Don River and a garrison was built at the channel to Toronto Harbour. Government buildings and a law court were established. Yonge Street was built, connecting York to the Holland River to the north. To the east, Kingston Road was built to the mouth of the Trent River. In 1797, the town site was expanded to the west to allow for public buildings and expansion. One of the new area's public functions, a public market, was started in 1803. It continues today as St. Lawrence Market.