Desperate Housewives star Eva Longoria has been tracing her family history in a new TV show.

The actress learned about her great-grandfather, Pedro Longoria, who lived in northern Mexico – a Spanish colony at that time – as she appeared on US show Faces Of America.

The show revealed that in 1749, Pedro took part in a mission led by the intrepid Spanish explorer José de Escandón.

De Escandón was under orders to push the Spanish frontier north and had advertised for people to go with him with the promise that they would be rewarded with free land.

Pedro was eventually given 4,500 acres of land by the King of Spain. His land was just north of Rio Grande, in what is known today as Texas.

The show is currently airing in the US and will also feature stars such as Meryl Streep and director Mike Nichols tracing their family tress.