He became a university lecturer in 1957, but his activities in opposition to the dictatorship of António de Oliveira Salazar led to repeated arrests.

There, for a short period he was taught geography by Álvaro Cunhal, who would later become the towering figure of Portuguese Communism and one of Soares' greatest political rivals.

Soares's multiple arrests for political activism made it impossible for him to continue with his career as a lecturer of history and philosophy.

Represented, particularly, Álvaro Cunhal when he was accused of several political crimes, and along with Adelino da Palma Carlos he also defended the dynastic cause of Maria Pia of Saxe-Coburg and Gotha Braganza.

In April 1964, in Geneva, Switzerland, Soares together with Francisco Ramos da Costa and Manuel Tito de Morais created the Acção Socialista Portuguesa (Portuguese Socialist Action).

In March 1968, Soares was arrested again by PIDE, and a military tribunal sentenced him to banishment in the colony of São Tomé and Principe in the Gulf of Guinea.

The new dictator wanted to present a more democratic face to the world, so many political prisoners, Soares among them, were released and allowed exile in France.

[4] In the October 1969 general election, which was rigged, the democratic opposition (whose political rights were severely restricted) entered with two different lists.

Soares participated actively in the campaign supporting the Coligação Eleitoral de Unidade Democrática or CEUD (Electoral Coalition for Democratic Unity).

In 1970, Soares was exiled to Rome, Italy, but eventually settled in France where he taught at the Universities of Vincennes, Paris and Rennes.

On 25 April 1974, elements of the Portuguese Army seized power in Lisbon, overthrowing Salazar's successor, Marcello Caetano.

The 1976 legislative election gave the Socialists a plurality of seats in the newly created Assembly of the Republic and Soares became prime minister.

Vast fiscal and currency account deficits generated by previous governments forced Soares to adopt a strict austerity policy, which made him deeply unpopular.

For most of Soares' two terms of office, Portugal was governed by the centre-right Social Democratic Party, led by Aníbal Cavaco Silva.

[5] He devised the so-called Presidência Aberta (Open Presidency), a series of tours around the country, each addressing a particular issue, such as the environment or a particular region of Portugal.