Currently, the Portuguese of Olivença and Táliga is not recognized by Spain, which has administered this territory since the War of the Oranges in 1801.

[6] Portuguese ceased to be the language of most of the population after the 1940s, a process accelerated by the Hispanicization policy implemented by Francoist Spain.

[5][7][8] The origin of Olivença is linked to the final conquest of Badajoz by the last king of León, Alfonso IX, in the spring of 1230.

[9] From these locations, around 1256, the Order created the encomienda of Olivença, at that time only a set of vegetable gardens, huts, and some houses around a spring.

[9] However, during the reign of Alfonso X, the Templars had to leave Olivença and give their lands to the Council and Bishopric of Badajoz.

During the Reconquista, the lands that today form the territories of Olivença and Táliga were ceded to Portugal by the Treaty of Alcañices, in 1297, along with many other localities.

King Denis had taken advantage of the weak Castilian political position to annex and retake several territories.

[2][11] Due to Olivença's peculiar geographical position, separated from the rest of the country by the Guadiana river and surrounded by Castilian settlements, it eventually developed a subdialect of Alentejan, with which it shares many of its isoglosses.

[14] Trait extended throughout the Galician-Portuguese linguistic area; in Olivença it is the general rule but there is also some conservation of the separation of the pronoun/defined article with the prepositions "para" or "a".

[14][22] This is a characteristic predominant in Portuguese informal speech, also present in Galicia where it is consecrated by the official orthography of the RGA; existing in Olivença.

[14][24][25] There is evidence in Olivença of words ending in "ão" forming the plural "ões" in situations where standard Portuguese does not.

[14] In Olivença, one finds the voiced elision of the adverb "não" ("no") and the verb that succeeds it, the latter needing to begin with a vowel.

[14] This is a trait common to some isoglossic pockets of the Alto Alentejo, but it is not universal in Olivença, and there are isolated cases of it in Campo Maior.

[14] In Olivença it is difficult to differentiate between the execution of the final vowel as a closed "e" or as an "i", the clearest cases being, for example, "cidadis", "possibilidadi" and "naceri"; in standard Portuguese: "cidades", "possibilidade" and "nascer", respectively.

A general trait of Alentejan and Oliventine speech also observed in Campo Maior, including in young people.

A trait also shared by other Alentejo villages, in Olivença, for example: "drento" e "preguntari" (standard: "dentro" and "perguntar").

The educational system of that time played a decisive role: it made children literate in Castilian.

[7] Previously, young people didn't go to school, but went to work in the fields when they were approaching puberty, so that Portuguese culture was preserved; Franco brought systematic schooling, together with the arrival of mass media, broke the isolation and made the Lusitanian culture that had been well preserved until then disappear.

[5] Since the Transition (Transición) and the return to democracy, relations with Portugal have been restored and interest in Portuguese culture, in general, has increased.

Portuguese architectural heritage is also being revalued, but a reluctant feeling towards Portugal and its culture still remains.

[7] In 2008, the association Além Guadiana was born, which has organized several events, colloquia, and programs to help keep alive the language in Olivença and to compile all the oral heritage of the Oliventine people.

[8][29] Além Guadiana's ambitious project is to create a sound database made of the recordings of the last Portuguese-speaking people of Olivença, this way, with the proverbs, stories, and songs, they document the recent history of the town.

[2] The Grupo dos Amigos de Olivença is a Portuguese nationalist organization, created under the Estado Novo.