Veterans of two Second World War battles that cost thousands of troops their lives have received the new Arctic Star medal and Bomber Command clasp.
The first of up to 250,000 presentations were made by Prime Minister David Cameron at a ceremony in Downing Street who hailed them as a "group of heroes".
The awards were announced last year after a long campaign to recognise the extraordinary bravery of those who fought in the war.
Mr Cameron told the veterans: "I can't think of a prouder day that I have had in this job or a group of people I am more honoured to share it with."
The Arctic Star is given to those who served in Arctic Circle, delivering supplies to the Soviet Union, primarily through the ports of Murmansk and Arkhangelsk.
They are credited by many with keeping up Russian morale in the fight against Nazi Germany.
The leading figure behind the campaign, Commander Eddie Grenfell, received his medal first in Portsmouth because he was too ill to travel to London.
Cdr Grenfell said he felt wonderful to be finally receiving it.
He said: "If I were to mention the names of all the good people who have helped me and my deputy Lt Cdr Dick Dykes to win our 16-year long battle against bureaucratic injustice, our visitors would have to extend their stay in our beautiful city, Portsmouth.
"I am, however, not so churlish to ignore the part played by our prime minister David Cameron in achieving today's success.
"He has, as I hear, always supported our claim for the award of the British Arctic Star but was hampered by bureaucracy, just as I was.
"It is just sad that so many of my comrades are no longer with us to receive their medals today."
The convoys, which sailed under the name Operation Dervish, cost 3,000 seamen their lives.
Winston Churchill once described their passage through the Arctic at the mercy of German forces as the "worst journey in the world". Only about 400 veterans are thought to be still alive.
Veterans of Bomber Command will also be recognised for their part in World War Two.
It has long been felt their exploits had been ignored compared to their compatriots in Fighter Command.
While Spitfires and Hurricanes provided valuable protection at home, Bomber Command attacked enemy sites abroad, flying dangerous sorties against munitions factories, ships and airbases.
Commanded by Air Chief Marshal Sir Arthur "Bomber" Harris, they flew missions over Germany, France and Italy.
One of the most famous was 617 Squadron's "Dambusters" raid in May 1943, during which bombs were dropped on the Mohne, Eder and Sorpe dams on the Ruhr in Germany.
Over 12,000 aircraft, including the famous Lancaster, were shot down during the war, with more than 50,000 airmen killed.
Caroline Dinenage, the Conservative MP for Gosport who campaigned for the medals, said: "The Arctic Convoy veterans endured unimaginable hardship to keep those vital supply chains open to Russia in the critical stages of WWII. They are all heroes in the truest sense of the word.
"After 10 years of campaigning, my delight to see justice finally being done is tinged with sadness that so many are no longer alive to receive the medals they richly deserved."
The Arctic Star and Bomber Command clasp were announced in December after a review by former diplomat Sir John Holmes.
The government moved quickly to design and manufacture the awards but critics say the recognition was due decades ago.
As well as veterans, the families of those who have died are able to apply to receive the awards on their behalf .