Privateer on shipping of a nation at war with France, on behalf of the French Crown. Seized vessels and cargo were sold at auction, with the corsair captain entitled to a portion of the proceeds. Although not French Navy personnel, corsairs were considered legitimate combatants in France (and allied nations), provided the commanding officer of the vessel was in possession of a valid Letter of Marque (fr. "Lettre de Marque" or "Lettre de Course"), and the officers and crew conducted themselves according to contemporary admiralty law. By acting on behalf of the French Crown, if captured by the enemy, they could
British and French declaration of war on Germany propaganda to justify German expansionism). Two Western powers, the United Kingdom and France, gave guarantees to Poland that they would declare war if Polish independence came under threat, as presented in a statement to the House of Commons by British Prime Minister Neville Chamberlain 31 March 1939 (formalized by the British 6 April 1939; not ratified until 4 September 1939 by the French): Although they honoured these guarantees by declaring war soon after Germany's Invasion of Poland on 1 September 1939, and although the dominions of the British Empire quickly followed suit, so little practical assistance was given to Poland,