Christmas in the Basque Country starts with the Feast of Santo Tomas on 21 December, a celebration in which most people go out onto the streets to dance and eat talo with txistorra (a type of Basque chorizo). They wear a traditional outfit called the casera dress. For girls it consists of a long skirt and a long-sleeved old-fashioned shirt with headscarves and aprons. The boys wear a long black shirt, trousers and txapela (traditional black beret). The casera outfits are normally dark blue, but can come in many colors. They wear caseras because that is what the people of the mountain wear and the holiday used to celebrate the peasants who sold their goods in town and came on Santo Tomas to pay rent to landlords in the city.
In the Basque Country the equivalent of Santa is Olentzero, and Olentzero lives or lived (depending on what you believe) in the mountains, and he wears the boys' casera. He is a mythical Basque character who is widely portrayed as a messenger who cries out that it is Christmas time throughout all the corners of the Basque Country. In some versions, the Olentzero is a farmer or a shepherd. Nevertheless, it is common in all of the tales that the Olentzero brings good news to people.
He is also known as the coal man who comes down from the mountains on his pottok (wild Basque horse) to hand out presents to children. Chestnuts and wine are given to the villagers. By tradition, on December 24, the Basque television and radio stations broadcast that the Olentzero has begun his journey from the mountains to children’s homes.
During the Franco dictatorship (1939 - 1975), Olentzero was banned as a symbol of regional separatism. It was only after this period that the tradition was restored to the Basque Country.