The Battle of Pinkie Cleugh, also known as the Battle of Pinkie, took place near Musselburgh, in Scotland, on the banks of the River Esk, on 10th September 1547. It was a battle of the "War of the Rough Wooing", so called because it started when Henry VIII tried to force Scotland to agree to a marriage between his son Edward and the infant Mary, Queen of Scots. The war began in December 1543 and it went on into Edward VI's reign, with Edward Seymour, Duke of Somerset and Lord Protector, continuing Henry VIII's policy of a forcible alliance with the Scots. The war was brought to an end by the Treaty of Boulogne in March 1550.
The Battle of Pinkie Cleugh is regarded as the last pitched battle between England and Scotland, i.e. a battle where both sides chose to fight at a scheduled time and location. The English forces, led by Edward Seymour, Duke of Somerset, defeated the Scots, led by the Earl of Arran. Somewhere between 6,000 and 15,000 Scots were killed at the battle, compared to 500-600 Englishmen.
The Battlefields Trust have created a number of resources on the Battle of Pinkie Cleugh and here are links to them: