Strong bonds between the RAF and Irish Air Corps are more important than ever, Ireland's most senior airman has said.
Brigadier General Sean Clancy, head of the Irish Air Corps, was speaking ahead of an event marking the RAF's centenary in Belfast.
He told an audience of serving and veteran RAF men and women: "In a very complex and volatile world the strength of our unity is even more important than ever."
The service at St Anne's Cathedral was part of the RAF 100 initiative.
Chief of the Air Staff, Air Chief Marshal Sir Stephen Hiller and Northern Ireland Under Secretary of State Shailesh Vara were in attendance alongside veterans, their families and other local dignitaries.
Offering congratulations on the "momentous occasion" General Clancy, whose uncle served with the RAF during the Second World War, added: "My presence here today symbolises those links and illustrates clearly that they continue.
"The Irish Air Corps was established in 1922 and the original 12 pilots for this fledgling air service came directly from the Great War and the Royal Flying Corps and subsequently the Royal Air Force.
"These pilots were the true beginning of this story of connection and unique links between our two services."
Northern Ireland became a vital base during the Second World War with more than 28 airfields stretching from the Ards Peninsual to Lough Erne primarily focused on winning the Battle of the Atlantic.
Aircraft based in Northern Ireland successfully sank many U-boats and assisted in the sinking of the Bismark.
The war efforts were assisted by a secret agreement with the Republic which permitted overflying of a corridor to the Atlantic in Donegal providing faster access to the sea for the Sunderlands and Catalinas operating off Lough Erne.
The region also played host to several Polish fighter squadrons.
Almost 12,000 men and women from Northern Ireland volunteered to serve in the RAF during the Second World War with 1,352 losing their lives.
The RAF is present in Northern Ireland through 502 (Ulster) Squadron -- the oldest of the reserve units - which has around 140 members and the newly formed Northern Ireland Universities Air Squadron.
Sir Stephen said the RAF 100 drive aimed to inspire two million young people throughout the world.
He said: "We want to inspire them to aim high, to achieve whatever they wish to do in the future to realise their ambitions and develop their potential.
"We in the air force feel that is the very essence of the organisation is giving people those sorts of opportunities.
"Being here (in Belfast) is a vital part of that - it is part of the commemoration, part of the celebration but it is also part of the inspiration."
Meanwhile, a great-grandson of Galway-born fighter ace Major William Robert Gregory said he was honoured and humbled to read the Yeats poem penned in his honour.
Robin Murray Brown, from Sussex, said: "I have been astonished by the number of comments I have heard from pilots in the air forces of almost every English speaking country when they talk about An Irish Airman Foresees His Death.
"That's the poem they have sellotaped on the inside of their cockpits and have done for much of the last 100 years.
"That is something that a lot of airmen have in common.
"That is just a very special thing."
Major Gregory joined the war effort in 1916 and was awarded the Military Cross for gallantry.
He was also awarded the Legion d'Honneur -- France's highest honour.
He died aged 36 when his plane came down over Italy in January 1918.