court dispute with Mr. Holder, owner of Aerco Jig and Tool of Birmingham. Beginning in 2000 export models started being labeled "Royal Enfield", at least for certain markets (I own a 2000 Royal Enfield). It appears in 2003 domestic bikes started being labeled "Royal Enfield" as well. Royal Enfield motorcycles have been sold in India for many years. The earliest record I could find was in the 1913 Indian TT in Calcutta. Madras Motors started systematically importing Royal Enfield motorcycles from the UK in the 1940's. Those bikes were obviously labeled "Royal Enfield".
The question is then: when did the transition from "Royal Enfield" to "Enfield" occur? David Blasco found a picture, allegedly from the mid 1960's, of the factory in Tiruvottiyur with bikes labeled "Royal Enfield". I have found pictures of pre 1990's bikes on the internet also labeled "Royal Enfield". In Gordon May's book "Made in India" there are also pictures from the 1960's of bikes labeled Royal Enfield (the picture of Nehru above is one of them).
So my best guess at the moment is that the "Royal" was dropped when the UK company went bust. At that time Royal Enfield UK was broken into pieces and sold by the E. H. Smith group. Norton Villiers Triumph (NVT) had acquired the twin operations in Westwood and its parent company, Bronze Manganese, had a stake in Enfield India whereas Velocette had acquired the parts division. When Royal Enfield stopped motorcycle production in 1970 and later Velocette closed in 1971 the name Royal Enfield passed to Aerco Tools, the company of Matt Holder. I guess at that time Enfield India felt it did not have the right to use Royal Enfield anymore? Was that the reason that the name could only be used after litigation in the UK? But aren't brands in the UK and India independent anyway? Or is there some quirk due to the Commonwealth? Does anyone know the precise story?