Factbox-Key facts about the Allied landings at Normandy on D-Day

80th anniversary of the 1944 D-Day landings in Colleville-sur-Mer

PARIS (Reuters) -American, British, Canadian and French leaders will commemorate the 80th anniversary of D-Day on Thursday.

Here are some facts about the Allies' D-Day landings in Normandy on June 6, 1944. The assault marked a decisive stage in the liberation of Europe from German forces in World War Two.

* Before D-Day, the Allies staged Operation Fortitude, which persuaded the Germans the landings would not take place in Normandy but in Pas-de-Calais, to the east. Dummy tanks, landing craft and planes were set up in eastern England.

* D-Day began in full on June 6, 1944, and was the assault phase of the Allied invasion of mainland Europe, or Operation Overlord. The Allied Supreme Commander was U.S. General Dwight Eisenhower. It should have started a day earlier but was postponed by 24 hours due to bad weather.

* In total, 156,115 Allied troops either landed by sea, onto beaches codenamed Utah, Omaha, Gold, Juno and Sword, or were airdropped behind German coastal defences. They included 83,115 British and Canadian troops and 73,000 U.S. troops, according to the United States European Command.

The Allies took approximately 10,250 casualties on D-Day - a number that includes killed, wounded and missing servicemen, according to the Commonwealth War Graves Commission. About 4,440 were killed.

German casualties are unknown but are estimated at between 4,000 and 9,000.

* Soldiers participating in the Normandy landings came from the United States, Britain, Canada, Belgium, Norway, Poland, Luxembourg, Greece, Czechoslovakia, New Zealand and Australia. Some 177 French commandos also took part.

* The landings and associated operations were codenamed Neptune and aimed to establish beachheads in northwest France.

* Nearly 7,000 ships and landing craft - of which 1,213 were naval warships - were deployed in Neptune and attacked German land and naval positions, landing troops and creating two artificial harbours which were towed across the Channel.

* Neptune officially ceased on June 30, 1944, by which time 850,279 men, 148,803 vehicles and 570,505 tons of supplies had been landed.

(Editing by Richard Lough and Andrew Heavens)