The Gloster Gladiator (or Gloster SS.37) was a British-built biplane fighter. It was used by the Royal Air Force (RAF) and the Royal Navy (as the Sea Gladiator variant) and was exported to a number of other air forces during the late 1930s. It was the RAF's last biplane fighter aircraft and was rendered obsolete by newer monoplane designs even as it was being introduced. Though often pitted against more formidable foes during the early days of the Second World War, it acquitted itself reasonably well in combat.
The Gladiator was being used as a home defence fighter by the RAF when the Germans launched their first attack on British soil. They were used to intercept Stukas because they were still more nimble than the heavy dive bombers. The Gladiator was also employed by the Norwegians against the Germans when they invaded their country in 1939. Against the Me-109, they fared poorly.
The Gladiator was also being used by the RAF during the siege of Tobruk in Libya against the Italians, where it held its own against the CR.42.