In 1758, with the capture of Louisbourg, Fort Frontenac, and Fort Duquesne, the war's momentum began to shift in favour of the British. Johnson was able to recruit more Iroquois warriors. In the summer of 1759, he led nearly 1,000 Iroquois warriors—practically the entire military strength of the Six Nations—as part of General John Prideaux's expedition to capture Fort Niagara. When Prideaux was killed, Johnson took command.