Development of the Gazelle began in 1966, after the French Army issued a set of requirements for a new helicopter to replace the Alouette II. Sud-Aviation (later Aérospatiale) began working on the project immediately and came up with a prototype within a year. The prototype, designated SA.340, conducted its maiden flight in April 1967 with success.
Further development of the helicopter continued, with the subsequent model - the SA.341 - receiving several improvements. Among them was the replacement of the conventional tail rotor with a fenestron tail, which integrated the tail rotor into the tail section. At this stage of development, the British Westland Helicopters company also became involved as the work turned into a joint project between the two companies, following an agreement signed in 1967.
Production of the SA.341 began in the late 1960s, with slightly differing models being produced for French and British armed forces. The first models entered service in the early 1970s. The helicopter would prove itself to be quite a success, which prompted further development to be pursued.
Further development of the Gazelle eventually resulted in the creation of the SA.342 - a more powerful modification fitted with an uprated engine. This modification also turned the Gazelle into a light tank hunter, being able to be fitted with HOT ATGMs.
The Gazelle also turned out be just as much of a success on the export market as it was with its initial operators. The helicopter type was widely exported to countries around the world and was even produced under licence by Egypt and Yugoslavia.
Although the Gazelle has long been replaced by newer helicopters, such as the Eurocopter Tiger for example, the type is still in active service with numerous nations today, including Great Britain and France. In total, over 1,750 Gazelles have been manufactured by 1996, taking into account all variants. These vehicles have been involved in many fighting conflicts, and are now used in Syria for Syrian army operations.