After the fall of France, various underground movements joined together to form the French Resistance. They engaged in guerrilla warfare, sabotage of German rail lines, and the publication of underground newspapers. They also operated 'escape lines' for downed Allied pilots and provided crucial intelligence to the Allies before the D-Day landings. General Charles de Gaulle, leading the 'Free French' from London, served as the symbolic head of the resistance. The resistance included people from all walks of life, including women like Nancy Wake (the 'White Mouse'), who became the Gestapo's most wanted person. Their efforts tied down numerous German divisions and boosted the morale of the occupied population.