Several years after NATO was formed, a requirement for a new light jet attack aircraft was issued in the form of a competition in 1953. The intention was to standardize the types of aircraft used by NATO members, an idea that tried to be implemented in not just aviation, but nearly all military branches. Several design bureaus entered the competition, with Fiat’s design being proclaimed the winner. 
The new aircraft, designated as G.91, while being a unique Italian design, was also influenced by the F-86K, an aircraft Fiat was already producing under licence. This design choice lead to Fiat not having to completely restructure the production process in order to adapt it for the manufacturing of new parts, thus in turn saving on production cost and time. 

The G.91 is remembered for being sturdy, nimble, very easy to fly and maintain. It was liked by both pilots and ground crew alike for ease of use and reliability. This is backed by the fact that the aircraft had a very high efficiency ratio with only a handful of breakdowns during its operational lifetime.  However, as with all things, the G.91 wasn’t perfect. The aircraft had a rather limited payload capacity and wasn’t the most stable firing platform. Although these shortcomings restricted the ground attack capabilities of the G.91, the aircraft’s redeeming qualities of reliability and ease of use, made it very popular among the ranks of the Italian, German and Portuguese air forces, whilst smaller numbers were employed by Greek and US air forces for testing purposes.

As the aircraft’s operational service was set during the cold war, it didn’t see much action in it’s lifetime. The only conflict it was used extensively in was in the Portuguese Colonial Conflict in the 60s and 70s in Africa. There, the aircraft proved to be very effective at combating the guerilla warfare employed by the nationalist movements, whilst suffering only a few losses from ground fire.  

However, due to the rapid development of new technologies in aircraft engineering and newer combat aircraft making their appearance, the G.91 was subsequently decommissioned from military service throughout the 70s. And though it’s military service had come to and end, the plane refused to retire just yet. The favorable flight characteristics made the airplane a very suitable platform to perform aerobatics with. This sparked the interest of the Italian national aerobatics team, who used slightly modified G.91s in their performances up until 1982, before the plane was ultimately retired for good. 
The G.91 had a long and, for the most part, peaceful service time of over 35 years in which it struck fear into the hearts of the enemy, and spread joy to delighted airshow spectators alike. In total, around 750 G.91s were produced between 1956 and 1977.