The last biplane fighter used by the Royal Air Force, the Gladiator entered service in 1937 although just two years later the type was considered obsolete and was being phased out of service. Despite this
during the Second World War the Gloster Gladiator would see action in the French and Norwegian campaigns during 1940 and the Battle of Britain. The aircraft was also used by the Finnish Air Force
during the Winter War and Continuation War.
In 1931 the Air Ministry were looking for a replacement for the Bristol Bulldog, despite already ordering the
Gloster Gauntlet, and this lead to Specification F.7/30 being issued on the 1st October 1931. This called for a fighter with a minimum
speed of 250 mph and armament consisting of four machine-guns. Despite a number of submissions no suitable aircraft was forthcoming so a further order for Gauntlets was placed.
Henry Philip Folland, Gloster's chief designer, took the Gauntlet design and examined it in detail to see the extent of which its performance could be improved. As a result of the design study the wings
were changed to single bay units, with the main spars strengthened and internally sprung landing gear installed. Although studies showed the promise of monoplane fighters the biplane design of
the Gauntlet was kept for the new aircraft. With the reduction in drag as a result of the changes a 10–15 mph improvement in top speed was expected. The prototype, designated SS.73, was flown
on the 12th September 1934 and a top speed of 236 mph was recorded using the Bristol Mercury IV engine. In November 1934 the installation of a Mercury VIS engine saw the top speed increase to 242
mph.
After submitting the new design to the Air Ministry during June 1935 a specification was written around the aircraft, F.14/35, however this required changes, including an enclosed
cockpit and the 830-hp Mercury IX engine being fitted. Three months later an order for 23 aircraft was placed. The 1st July 1935 saw the aircraft's name of Gladiator being announced. July 1936
saw the first order of Gloster Gladiator Mk Is being delivered carrying two Vickers guns mounted within the fuselage and two Lewis guns under the wings. Another order was placed, however
the second batch had a universal armament mounting under each wing which would accept either Vickers, Lewis or Colt-Browning machine guns. The Colt-Browning was installed in both the
wing and fuselage for the majority of aircraft delivered in 1938.
The Gladiator Mk I entered service with the re-formed No. 72 Squadron at RAF Tangmere on the 22nd February 1937. The Mk I had a top speed of 253 mph, a range of 428 miles, a service ceiling of 32,800 ft and
armament of four 0.303-in machine-guns. A little over two years later No. 72 Squadron, along with other squadrons equipped with the type, were already being re-equipped with either the
Supermarine Spitfire or
Hawker Hurricane. The RAF also took delivery of the Mk II fitted with a 856-hp Bristol Mercury VIIIA which had
specifically been fitted with gun synchronisation gear for the type. With the same armament as the Mk I the Mk II offered a slight improvement in speed, range and service ceiling.
Despite being outdated two Gladiator squadrons, No. 607 and No. 615, would provide air support as part of the British Expeditionary Force when they were sent to France in September 1939. Against the
modern fighters of the Luftwaffe they would suffer heavy losses. No. 46 Squadron would also take the type into action during the Norwegian campaign between April and June 1940.
As part of the Fighter Flight, RAF Sumburgh, later No. 247 Squadron which re-formed on the 1st August 1940, a flight of Gladiator Mk IIs would see combat during the Battle of Britain. First over the
Shetland Islands before moving to RAF Roborough as part of No. 10 Group, Fighter Command. The Gladiator also saw action in the Mediterranean and saw combat against the Fiat CR.32
and Fiat CR.42 biplanes of the Italian Air Force. Gladiators also served with Coastal Command.
The Gladiator would also be used by a number of Air Forces world wide. The Chinese Nationalist Air Force operated 36 during the Second Sino-Japanese War (1937-1945), and it was whilst serving with the Chinese Nationalist Air Force that the type first
saw combat and scored its first aerial victory. This occurred on the 24th February 1938 over a Mitsubishi A5M. The Finnish Air Force used the Gladiator in the Winter War (1939 - 1940) and Continuation War (1941 - 1944)
against the Soviet Union. Other operators of the Gladiator included the air forces of Belgium, Greece and Norway, who had a number in service, when Germany invaded the country on the 9th April 1940 along
with Denmark as part of 'Operation Weserübung'.
When production of the Gladiator ceased a total of 648 had been built and it would stay in service with the Royal Air Force after their front line service had ended where, until 1944, they were used for communications, liaison and metrological use.
A naval variant known as the Sea Gladiator was produced with 60 built and around 40 converted Mk IIs. These were fitted with an arrestor hook, catapult points and dinghy storage.