This Europe: How two brothers in Braga broke with Latin

Portuguese is one of the world's most widely spoken languages and this week it became an official language of the newest country, East Timor.

Now, researchers have found the oldest known document in Portuguese: an agreement by two brothers from Braga to defend their farms against raids in the 12th century.

Jose Antonio Souto, professor of language history at Spain's Santiago de Compostela University, told a conference in Braga this week that the undated pact predates 1175 – until now the date of the oldest document in Portuguese. In the pact, the brothers agreed not to make any claims on each other's farms and to defend them against anyone who did.

Mr Souto said their words represented the first clear break from Latin. On the back of the document is a contract for a land sale from 1175, which Mr Souto said must have postdated the pact.

Braga is on fertile land in northern Portugal between the rivers Este and Cavado. In the 12th century, the city was gaining in importance under the reign of Dom Alfonso Henriques, the first king of Portugal. It became the home of several rich landowners as well as the Catholic Church. Braga became known as "the Rome of Portugal".

Portugal's Publico newspaper said several texts from the late 12th century had been found in the region, allegedly written in Portuguese and dating back to 1175 but no earlier. Some historians, however, argue that the small handwriting of these texts makes them almost impossible to distinguish from Latin.

The mother tongue spread with the growth of Portugal's empire and today there are about 180 million speakers of Portuguese worldwide.