The Battle of Flodden, Flodden Field, or occasionally Branxton, (Brainston Moor) was a battle fought on 9 September 1513 during the War of the League of Cambrai between the Kingdom of England and the Kingdom of Scotland, resulting in an English victory. The battle was fought near Branxton in the county of Northumberland in northern England, between an invading Scots army under King James IV and an English army commanded by the Earl of Surrey. In terms of troop numbers, it was the largest battle fought between the two kingdoms.

After besieging and capturing several English border castles, James encamped his invading army on a commanding hilltop position at Flodden and awaited the English force which had been sent against him, declining a challenge to fight in an open field. Surrey's army, therefore, carried out a circuitous march to position themselves in the rear of the Scottish camp. The Scots countered this by abandoning their camp and occupying the adjacent Branxton Hill, denying it to the English. The battle began with an artillery duel followed by a downhill advance by Scottish infantry armed with pikes. Unknown to the Scots, an area of marshy land lay in their path, which had the effect of breaking up their formations. This gave the English troops the chance to bring about a close-quarter battle, for which they were better equipped. James IV was killed in the fighting, becoming the last monarch from Great Britain to die in battle; this and the loss of a large proportion of the nobility led to a political crisis in Scotland. British historians sometimes use the Battle of Flodden to mark the end of the Middle Ages in the British Isles; another candidate is the Battle of Bosworth Field in 1485.