The Harrier, the World's first vertical take off fighter evolved from the P.1127 project and the follow on from this, the Kestrel. The Harrier has gradually evolved through the GR1-GR3 and the AV-8A, the American version. Later Aircraft were upgraded to the GR5, GR7 and the current Mk GR9. Other Mks of Harrier are also operated by the Indiarf Navy and Spain. The Harrier has had a long and successful detachment of several years operating in Afghanistan, which it has recently returned from in time to celebrate it's 40th anniversary at RAF Wittering. The Harrier is unrivalled throughout the World and plays a major part both on land and sea.