Hundreds of parades and displays have taken place across the country to mark Armed Forces Day.
The annual event, now in its eighth year, saw hundreds of thousands of people turn out in support of servicemen and women, including regulars, reserves and veterans.
David Cameron attended a national event in Cleethorpes, North East Lincolnshire, alongside the Duke of Kent to see displays by the Red Arrows, the RAF Falcons parachute team and the Royal Marines, who performed a beach landing.
The Military Wives Choir, the White Helmets motorcycle display team and a Chinook helicopter also entertained the large crowd ahead of a firework spectacular rounded off the day.
The outgoing Prime Minister said: "It made me incredibly proud to be in Cleethorpes today to see so many people showing their support for our armed forces. As Prime Minister I have seen first-hand the amazing job that the men and women of all three services do.
"Whether taking the fight to Daesh in Syria and Iraq or helping to deal with emergencies in the UK - their sacrifice keeps us safe.
"It is right that we show our support, both by holding events such as this and ensuring that that those who serve or have served, and their families, are treated fairly.
"That is why we are helping thousands of forces families to buy a home and supporting their children with additional educational funding."
Defence Secretary Michael Fallon paid tribute to military men and women serving across the world from those fighting Islamic State in the Middle East to those training troops in Nigeria.
He said: "In the last few years alone, our regulars and reserves have helped stamp out Ebola in Sierra Leone, protect the Baltic skies, rescue thousands of migrants in the Mediterranean and help hundreds of UK flood victims at home.
"And our debt of gratitude extends to the families they leave behind, and the veterans past and present who have dedicated years of their lives to service. It is only right that we salute them today and celebrate their achievements."
Among the veterans involved in the event was Jack Bond, 96, who took part in the D-Day landings during World War Two.
Mr Bond, who has been awarded France's highest military honour, the Legion D'Honneur, was stopped in the street by members of the public who wanted to shake his hand.
His wife Diane, from Grantham, said: "It's a very proud day for us - I'm proud whenever I see him with his medals."
Sergeant Simon Peat, 44, of 102 Battalion, The Royal Electrical and Mechanical Engineers, was among the serving soldiers who marched in the parade as it passed along the seafront of his home town.
He said: "Parading through Cleethorpes was a hugely humbling experience for me. Today has been absolutely fantastic, I've never seen so many people here, giving this place such a sense of joy.
"It just shows that events like this really brings people together."