Who Are Irish Travellers?

Irish travellers are a nomadic people who make up about 1% of the population in Ireland (20,000-30,000).  Another 15,000 live in Britain and perhaps 7000 in the USA.  They are a distinct cultural group from the "settled" population.  Although often called "gypsies" in English, they are culturally very distinct from Romany nomads.  Travellers were first recorded in Ireland in the late middle ages, although their numbers have probably fluctuated a lot over the centuries.

Their origin is hotly disputed, but it seems likely they were poor people who turned into permanent migrant workers, and not wealthy people deposed off their lands centuries ago, as is sometimes suggested.

In addition to English, they speak Shelta.  Shelta vocabulary most comes from Irish (the celtic language Gaeilge), but also borrows from Roma and English.  The grammarical structure and syntax of Shelta is based on English, though.

Travellers practice a custom of early marriage for girls, and marriage to close relatives (first or second cousins).  They do not tend to value education and they also suffer disproportionately from health problems exacerbated by their migratory lifestyles.  Most are self-employed and much dispute is made over whether they pay a fair share of taxes (particularly income tax).
Prejudice against the Travellers is very strong in Britain.