She is the second of the three Invincible class aircraft carriers and was laid down in 1976 at Swan Hunter on the River Tyne as Yard No. 102. She was launched in 1978 and formally commissioned on 20 March 1983.
She has a displacement of 22,000 tonnes, 209m Length, 36m beam and 7.7m draught and is powered by 4 Rolls-Royce Olympus TM3B gas turbines providing 97,000 hp (75 MW). These give her a top speed of 30 knots and a cruising range of 5000 nautical miles at 18 Knots.
Her full complement consists of 685 crew in addition to 366 Fleet Air Arm personnel.
Armament consists of 3 × Goalkeeper CIWS (Close In Weapon Systems), these are 7 barrelled 30mm calibre weapons with a rate of fire of 4200 rounds/ minute and an effective range of between 350m and 2000m depending on ammunition type together with 2 × GAM-B01 20 mm close-range guns.
She can also carry up to 22 helicopters.
Although she was completed too late to take part in the Falklands War she was deployed to the South Atlantic after hostilities and remained on station until the airfield was repaired.
Since the 1980's she has taken part in numerous operations in many different parts of the World.
Illustrious now acts as a helicopter carrier following the recent axing of her Harrier contingent and is due for withdrawal from the Royal Navy in 2014.