In France, the new revolution overthrew Louis Philippe in 1848. Louis Napoleon became the President, then the Emperor of France. To intervene in Vietnam and also expand the French Empire, on 22 April 1857 Napoleon III created the Committee de la Cochinchine with Baron Brennier as its chairman, with purposes was a plan to conquer Vietnam and capture the Vietnamese monarch, using Tự Đức's persecution of Catholics and the undone treaty of 1787 as pretexts for the conquest. In the same year, Tự Đức executed two Spanish Dominican priests; France and Spain declared war and launched the invasion of Vietnam.