When the Mimosa sailed from Liverpool in 1865, its passengers envisaged a new Wales set in the windswept plains of Argentina. The stone chapels in the Chubut valley of Patagonia still stand as testimony to the success of these early Welsh pioneers.
Yet the most remarkable legacy of the 153 settlers who disembarked on Argentine soil 140 years ago this month is the persistence of the Welsh language.
"It's a miracle in a way that there are still generations of Welsh speakers in Patagonia today," says Robert Owen Jones, a professor at Cardiff university, who has been studying the Welsh in Argentina since the early 1970s.
"The language wasn't even recognised in Wales when the first settlers came.
Yet even the German communities in Bariloche (west Patagonia) haven't maintained their language so long, despite it being a state language."
This endurance has several causes. The sheer remoteness of the region meant there was no other culture with which to assimilate initially. And the early colonists had to stick together for survival. What distinguished the Welsh Argentine adventure, however, was the settlers' ideological drive to protect their national linguistic, cultural and religious customs.
"The whole ethos of this Patagonia movement was to retain their identity.
The first thing they would do when they moved to an area would be to build a chapel. These were used as schools as well as for church services and midweek meetings, and therefore became the focal point for the community," says Professor Jones.
The Welsh were not left alone for long, however. By the late 1890s, the Argentine government had decreed that all public education should be in Spanish.
By the 1940s and 1950s, the simultaneous rise of Argentine nationalism and the gradual weakening of the chapel movement pushed the Welsh language into crisis. "Lots of people used to be a bit shy of speaking Welsh," confirms Luned Roberts de Gonzalez, a retired headteacher in the Welsh Patagonian town of Gaiman, who can trace both sides of her family back to the Mimosa.
"At school, they insisted that you had to speak only Spanish and people laughed at you if you had a Welsh accent. I've never had an inferiority complex because I speak Welsh, but it wasn't the case with everybody," she says.
Welsh in Argentina was saved by the return of democracy in 1983, which brought a new respect for minority groups and a renewed interest in the country's immigrant heritage.
In recent years, visitors from Wales have also boosted the language. Young volunteers and retired teachers began arriving in the mid-1980s to teach Welsh. The efforts of these "missionaries of the language", as Luned describes them, were formalised into a language learning programme funded by the Welsh Assembly in 1997.
This sends three teachers from Wales every year, and provides six scholarships for Welsh learners in Patagonia for an intensive two-month language course at the University of Wales in Lampeter.
Gabriel Restucha, 33, is a graduate of the scheme. A decade ago, he spoke no Welsh, despite his grandmother being a fluent speaker. Now fluent, he teaches Welsh in Gaiman and the surrounding area. His students include Quechua-speaking Bolivian immigrants, and his mother.
"For me, the opportunity to learn Welsh and go to Lampeter was a life-changing experience," he says. Interest in Welsh cultural activities, such as the annual Eisteddfods that now take place in Trelew, Gaiman, Esquel and other Welsh Patagonian towns, is also drawing in Argentines of non-Welsh extraction.
Many Patagonians simply enjoy the learning process. "I have no Welsh descendants, but I study Welsh because it's difficult, a challenge," says Alejandra Vilela, 39, a biologist from Buenos Aires now living in Trelew.
The survival of Welsh in Argentina also represents a challenge. But Professor Jones is confident. "People are now proud to say they have Welsh roots, even if they don't speak Welsh. Or they're proud to say, 'I'm learning, or trying to learn'."
Oliver Balch is a freelance journalist.