In July 1759, two thousand three hundred British and New York troops, joined by about nine hundred Iroquois allies, laid siege to French-held Fort Niagara. The attack followed established European siege methods even in the North American wilderness: beginning about one thousand yards from the fort, the attackers dug a zigzag trench, or sap, reinforced with gabions and fascines to shield their advance from enemy fire, then built artillery batteries as they moved closer. The British landed at Four Mile Creek on July 6 and skirmished with French scouts, marched to camp east of the fort on July 8, and on July 9 Captain Walter Rutherford delivered a surrender demand that Captain Pierre Pouchot refused. Trench digging began on July 10; by July 17 the British had opened artillery batteries about three hundred to four hundred yards from the fort and bombarded the walls with solid iron cannonballs weighing six to eighteen pounds. On July 20 General John Prideaux was killed and Sir William Johnson took command. By July 23 a new battery stood only one hundred yards from the fort's outer works, while French guns were repeatedly knocked out and remounted. On July 24, at the Battle of La belle Famille one mile south of the fort, a French relief force was defeated, and with its wall breached and relief cut off, Fort Niagara surrendered on July 25, nineteen days after the siege began.