On July 12, 1690, the Battle of Bonnie broke out. On July 12, 1690, the Battle of Bonnie broke out. King William III led an army of 3,60,000 Protestant troops and confronted 25,000 Catholic troops led by King James II on the banks of the Bonnie River in Ireland. After a bloodshed battle, the army of William was victorious. James II's army lost more than 1,500 people, and William's army lost only half of it. The battle became the largest battle on modern Irish soil. James II lost local Catholic support because of feebleness in the battle. Battle of Bonnie: The final support of the Catholic Church of England to Ireland was gradually annexed by the British.