 For a time, starting in 1651, the Nguyễn themselves went on the offensive and attacked parts of Trịnh territory.However, the Trịnh, under a new leader, Trịnh Tạc, forced the Nguyễn back by 1655.After one last offensive in 1672, Trịnh Tạc agreed to a truce with the Nguyễn Lord Nguyễn Phúc Tần.