1866: the Irish invade Canada. The Irish independence cause spilled over to the rest of the world in interesting ways. In the Battle of Ridgeway, Irish republicans attempted to seize Canada to pressure the UK to leave Ireland.
They didn’t come all the way from Ireland: the Fenian Brotherhood was a collection of Irish republicans living in the United States. More than a thousand irregulars wanted to contribute to the cause, and so gathered together arms and crossed the Niagara River on June 1.
They ran into Canadian and British soldiers, and the battle was on. It must have been a polite battle: 6-8 Fenians died, 9 Canadians were killed in action and another 22 died from wounds or disease, and it ended when a (probable) misunderstanding caused the Canadian forces to retreat.
It was the first modern battle fought by Canadian troops, and Wikipedia calls it “the only armed victory for the cause of Irish independence between 1798 and 1919.”