A document of 1530 reports that a group of "Egyptians" danced before James V.

This was presumably one of the exotic bands dispersing through Europe at the time and claiming - mostly without success - protection from the "King of the Romans" (Holy Roman Emperor) or the "Duke" or "Earl of Little Egypt". Ever since, children have been taught (and Philip Pullman has only encouraged the notion) that gypsies somehow originate from the land of the Pharaoahs.

The origin of this may be quite simple. Facing suspicion and persecution, gypsies regularly temporise and obfuscate their own backgrounds. "Egyptian" may have been a conveniently romantic self-designation or it may simply refer to a port in the Peloponnese known as "Little Egypt" where there is strong evidence that gypsies gathered during their steady westward push.

The evidence for a Greek sojourn is largely linguistic, and such methods prove clearly that the gypsies' original homeland was India. The Romani tongue is strikingly close to elements of Hindustani but, like Yiddish, has naturalised and split into umpteen dialects when exposed to the languages of domicile.

Serious study of Romani began in the 18th century, sometimes sympathetic, sometimes hostile in a manner which leads directly to the Holocaust, and writers and artists have always been drawn to the speech, lifestyle and iconography of the glamorous gypsy. Matras briefly mentions George Borrow, author of Romany Rye, but not, strangely, his own great predecessor Walter Starkie, an Irish linguist who made a specialist subject of the Spanish "raggle-taggle".

I Met Lucky People takes its title from the Romani "national anthem" Gelem, Gelem, written in 1949 by the Serb Romani musician }arko Jovanovic, who survived three concentration camps but lost most of his family to the Nazis. It is a one-volume history of a people who, to the best of anyone's knowledge, have never waged war and never had a fixed homeland. The Roms' story is all diaspora and no centre.

The best one-line description of their origins - which improves on the muddle of definitions offered up by well-intentioned and politically correct governments across the developed world - is that the "early migration of the Roms was part of a steady movement of caste-like groups specializing in service trades who left India and migrated westwards".

Matras was media officer to the Roma National Congress for nearly a decade. He is used to issuing corrective statements, combating the notion that to be a gypsy is a lifestyle choice or branch of sociopathy, and above all to putting straight a confusion of Rom gypsies with Travellers and other gens du voyage.

The cultural impact of the Roms goes deep and dark. Though gypsies are portrayed in fiction (step forward DH Lawrence) and painting as soulful and erotic, they are often modest to the point of prudishness. A distant aunt declined to walk upstairs (this is one reason why gypsies generally prefer to live in one-storey dwellings) when there were men in the house because it meant her lower body and limbs were elevated above them.

A complex system of protocols and taboos influences gypsy life, further complicated by contact with the established religions (Catholic, Evangelical, Orthodox, Muslim) by which Roms maintain some contact with mainstream society. But this is less interesting than images of full-bosomed women dancing (or fighting) round a campfire, festooned with gold and bright colours. For many, "gypsy" and "hippy" seem one and the same.

A search on Allmusic suggests that there are more rock songs with "gypsy" in the title than almost any subject other than "love".

When folk-singer Vashti Bunyan left London for Skye in the 1960s, she came, naturally enough, in a gypsy caravan. Half-way along that journey there are strong evidences of gypsy culture. Youngsters' slang in Berwick-on-Tweed and Hexham is a form of Romani cant; we owe words like "chav", "pal", "gadge" and "minge" to Romani.

Scottish gypsies belong to the same Kaale tribe as those in Finland; English gypsies are Romanichal, Spanish are Gitanos. A centre for the study of gypsy folklore was established in Edinburgh in 1888. But this is a global story. Rom communities exist across the world, often different one to the other. By no means defined by movement (80% stay put or are sedentarized by circumstance) nor by fortune-telling, they are drawn together in an age of electronic communication by a new social and intellectual confidence and the potential to share in real-time the rich differences that exist within one of the world's great languages.

Yaron Matras will be discussing his book at Aye Write! on Saturday April 12