World leaders will gather in Normandy for an emotional ceremony expected to be the pinnacle of events marking the 70th anniversary of D-Day.

Up to 19 heads of state, including the Queen, US President Barack Obama and Australian Prime Minister Tony Abbott, will be on Sword Beach near Ouistreham, one of the five battle zones on Normandy’s coastline on June 6, 1944.

The ceremony is expected to mark the high point of the anniversary events, which has seen thousands flock to beaches, cemeteries and villages linked to the momentous landings.

The day’s commemorations began at midnight with a vigil at the Pegasus Bridge, marking the first assault of the D-Day invasion when Allied soldiers landed in the dead of night exactly 70 years ago.

At 12.16am a team of six Horsa gliders carrying 181 men from the Glider Pilot Regiment and the 2nd Battalion, Oxfordshire and Buckinghamshire Light Infantry, landed silently to capture the strategically-vital bridge and another nearby, paving the way for soldiers landing on the Normandy beaches to move inland and reinforce their airborne colleagues.

Their feats were also recognised on Thursday when the Prince of Wales laid a wreath at the exact spot where one of the gliders landed, before meeting veterans of the Glider Pilot Regiment and their families with the Duchess of Cornwall.

It was at Sword Beach that thousands of troops came ashore from the Channel to help turn the tide of the Second World War into an eventual victory against the tyranny of Nazi Germany.

For many veterans, now in their late 80s and 90s and who have made the annual pilgrimage to honour the 156,000 Allied troops who stormed the beaches, this year’s events will possibly be their last at the scene of their exploits.

At Sword, French President Francois Hollande will deliver a speech, followed by Obama. A re-enactment of the momentous events 70 years ago is due to be the main focus of the ceremony.

A 21-gun salute and a flypast will also form part of proceedings, but the French authorities are keeping a tight lid on exact details amid a huge security operation across the region.

The Queen – who is in the middle of a three-day state visit to France – will travel from Paris to take her place at the ceremony along with Abbott, David Cameron and German chancellor Angela Merkel.

Russian President Vladimir Putin will also be at Sword Beach, in a potentially awkward encounter with Western leaders following disagreements over Ukraine.

In a potentially added twist, Ukraine’s new president Petro Poroshenko is also expected to be attending the ceremony.

The main international D-Day ceremony will mark the climax in this week’s commemorative events remembering an operation described by prime minister Winston Churchill as “undoubtedly the most complicated and difficult that has ever taken place”.

D-Day heralded the beginning of an 80-day campaign to liberate Normandy, which involved three million troops and cost 250,000 lives.

The Duke and Duchess of Cambridge will also play a role by attending events in Arromanches, near the Gold landing beach where thousands of British troops came ashore on D-Day.