This year marks the 75th anniversary of the Battle of Normandy and the D-Day landings, which saw more than 60,000 British troops land on the beaches of Normandy to fight Nazi Germany.
A host of events will be taking place around the UK to commemorate those who fought during the D-Day operation in 1944, paying tribute with military parades, flyovers, firework displays and festivals.
If you're keen to learn more about the historic day, here are 15 fascinating facts you might not know.
The 'D' stands for 'Day'
The 'D' in D-Day simply stands for the word 'Day'.
D-Day is used as a general military term for the day on which an operation begins, although it is now typically only used to refer to the Allied landings in Normandy.
A pigeon delivered the first D-Day news
Thousands of pigeons were drafted for Allied service during World War II, with a bird named Gustav being responsible for bringing the first report of the Normandy landings to the British mainland.
Gustav traveled 150 miles on D-Day to reach RAF Thorney Island to relay the message that the allies had landed.
D-Day was delayed by the weather
D-Day was originally planned for 5 June 1944, but it had to be delayed 24 hours due to poor weather conditions.
The weather was still not ideal on 6 June, with strong winds and rough seas making the landings difficult, but further postponement would have pushed the invasion back to 19 June, when a severe storm hit the Channel, and increased the chance that plans would be detected.
Strong winds and rough seas made the landings difficult (Photo: Shutterstock)
Parachuting dogs were enlisted to help
The 13th (Lancashire) Parachute Battalion enlisted dogs into their ranks for D-Day, with the pups trained to locate mines, keep watch, sniff out enemy positions and warn about incoming troops, helping to save many Allied lives.
There was a codename
The successful invasion of Nazi-occupied Europe was codemaned 'Operation Overlord'.
There was a fake army
A fake army made up of inflatable tanks and trucks was set up in Kent, in an effort to trick the Germans into thinking the invasion would take place in the Pas-de-Calais
The deception plan also had a codename
The deception plan intended to keep the Germans guessing as to when and where the invasion would take place was codenamed ‘Operation Bodyguard’.
Forces on D-Day primarily consisted of American, British and Canadian troops (Photo: Shutterstock)
D-Day was an international effort
More than two million troops from more than 12 countries were in Britain in preparation for the invasion, with forces on D-Day consisting primarily of American, British and Canadian troops.
Forces from Australia, Czechoslovakia, France, Norway and Poland also assisted in the effort.
There were sparks of romance
US soldiers assisting with the effort were very popular among young British women, thanks to earning around £12 per month.
More than 70,000 British women married American servicemen during the war.
British infantry earned much less than the US
The basic pay for a British infantryman was three pounds and 15 shillings per month - much lower than US soldiers, who earned around £12 per month by comparison.
Some information was more than 'Top Secret'
All information relating to the invasion was marked 'BIGOT' - a security classification even higher than 'Top Secret'.
Those on the 'BIGOT' list (which stood for the British Invasion of German Occupied Territory) had knowledge of the D-Day planning work, including the landing beaches and the date of the invasion.
They were also banned from travelling outside of the UK in case they were captured and coerced into revealing top secret information.
There was a lot of planning
In the build up to D-Day, around 17 million maps were drawn up in preparation to execute the invasion.
Around 17 million maps were drawn up in preparation for the invasion (Photo: Shutterstock)
The invasion required a LOT of vessels
Around 7,000 vessels were used by the Allies on D-Day, with more than 4,000 landing craft used to transport the invasion force onto the beaches of Normandy
And a lot of soldiers
Around 83,000 British and Canadian troops, and 73,000 US troops, crossed the channel on D-Day, with the crossing taking about 17 hours.
The surprise attack paid off
Only Hitler could issue the order to the German Panzers to counter-attack the Allied invasion on D-Day, but he slept until midday on 6 June.
By the end of the day, the Allies had established a foothold along the Normandy coast, allowing them to begin their advance into France.