In August, the British finally launched their campaign to capture New York City. They first landed on Long Island in force, and flanked Washington's forward positions in the Battle of Long Island. Howe refused to act on a significant tactical advantage that could have resulted in the capture of the remaining Continental troops on Long Island, but he chose instead to besiege their positions. In the face of a siege he seemed certain to lose, Washington then decided to withdraw. In what some historians call one of his greatest military feats, executed a nighttime withdrawal from Long Island across the East River to Manhattan to save those troops.