The English army crossed the Tweed River on 28 March 1296 and proceeded to the priory of Coldstream, staying there overnight. The English army then marched towards the town of Berwick, Scotland's most important trading port, at that time. Berwick's garrison was commanded by William the Hardy, Lord of Douglas, while the English army was led by Robert de Clifford, 1st Baron de Clifford. The English succeeded in entering the town and began to sack Berwick, with contemporary accounts of the number of townspeople slain range from between 4,000 and 17,000. The English then began a siege of Berwick Castle, whereupon Douglas surrendered it upon conditions that his life and those of his garrison were spared.