The 100th anniversary of the Royal Air Force is putting the spotlight on the role Sheffield and South Yorkshire has played defending Britain in the skies.
Tomorrow - April 1 - marks a century since King George V authorised the creation of the new military branch in recognition of the growing importance of air power in warfare.
And the force once had a high-profile presence locally.
In Sheffield, there was RAF Norton, which started as No 16 Balloon Training Centre in 1939 with three squadrons of barrage balloons to fend off attacks. The base, spread across 155 acres, is remembered for the Spitfire that was posted at the main gates.
At its height it had 400 airmen but when the flag was finally lowered on January 29, 1965, there were just 15 officers and men left. The land off Norton Avenue was once earmarked for a third big hospital, to complement the Royal Hallamshire and Northern General, but has been used since 2014 for driving lessons.
Meanwhile, passengers catching flights today from Doncaster Sheffield Airport are treading on the former site of RAF Finningley. The first airfield was built there in 1915, and RAF squadrons arrived in 1936. The first craft to land at the station were three Vickers Vimy biplanes.
Throughout World War Two and the Cold War, it was the front line bomber command base, and also acted as a centre for training pilots and crew. The Vulcan nuclear bombers famously flew from Finningley, but in 1996 the facility was closed by the Ministry of Defence as part of defence cuts. Peel Holdings bought the land and turned it into a commercial airport - the first of its kind for over 50 years - that launched in 2005.
Commemorations will happen this year in the county. In Doncaster, a concert is taking place on October 10 at the Cast Theatre with the Band of the RAF College, while on June 30 a special service is to be held at the war memorial on Market Street in Penistone. Nationally, RAF 100 events will include a flagship parade and flypast in London on July 10, and a baton relay which starts tomorrow, visiting 100 notable sites in as many days. A countrywide aircraft tour is also stopping in Manchester city centre on September 15 and 16.
The RAF's formation followed a review of British air power in response to the German deployment of long-range Gotha Aircraft during World War One, which were capable of striking the British Isles.
The Royal Naval Air Service and the Royal Flying Corps merged together on April 1, 1918, creating the world’s first independent air force. On that day, Bristol F.2B fighters of the 22nd Squadron carried out the newly-established force's first official mission.
By the end of the conflict, in November 1918, the Royal Air Force had established air superiority on the western front. During the post-war period the RAF's 22,000 planes had dwindled to an operational strength of 2,000 by 1939, but the outbreak of World War Two saw the RAF again called into action to defend Europe.
Its finest hour came during the Battle of Britain, when the pilots of the RAF, in the cockpits of Supermarine Spitfires and Hawker Hurricane fighters, successfully repelled the superior numbers of the Luftwaffe, causing the German command to delay the invasion of Britain indefinitely.
When hostilities ceased in 1945 there were nearly one million active RAF personnel, a number which has stabilised and gradually reduced over the years as the British armed forces have sought to keep pace with changes in modern warfare.
The modern day organisation has 34,034 active personnel, including 1,143 reservists, and the Spitfires and Hurricanes have been replaced with Eurofighter Typhoons and F35 Lightning Jets.
A campaign - the RAF100 Appeal - has been instigated by charities to support the force's veterans and serving members.
Speaking last year, chief of the air staff, Air Chief Marshal Sir Stephen Hillier, said: “Our first 100 years of excellence is down to the remarkable dedication and achievements of the men and women of the Royal Air Force. Together with our nationwide set of public events and education initiatives, the appeal will help to ensure that we have a legacy which will take us beyond 2018 and long into our second century."
Visit raf100appeal.org to find out more.