Lower Canada Rebellion
When news of the arrest of the Patriote leaders reached Upper Canada, William Lyon Mackenzie launched an armed rebellion in December 1837. In the meantime, filibusters from the United States, the Hunter Patriots, formed a small militia and attacked Windsor, Upper Canada, to support the Canadian Patriots. This resulted in the declaration of martial law by the Lower Canadian government.
Patriot War
While the initial rebellion in Upper Canada ended quickly with the Battle of Montgomery's Tavern, many of the rebels (including rebel leader William Lyon Mackenzie) fled to the United States. Mackenzie established a short-lived "Republic of Canada" on Navy Island in the Niagara River, but withdrew from armed conflict soon thereafter.