The historic leader of the Portuguese Socialist Party, known in Portugal as one the Founding Fathers of the democratic era that started in Portugal in 1974, died following respiratory complications that left him in a deep coma since late last year.

Prime Minister António Costa said the government is declaring three days of national mourning starting Monday for Soares, and that the former President’s funeral will have State Honours.

Mário Soares served in the highest offices in the Portuguese political landscape: he was prime-minister, President of the Republic, and Portuguese MP to the European Parliament.

Born on 7 December 1924 in Lisbon, Mário Alberto Nobre Lopes Soares founded and was the first leader of the Socialist Party and was Minister of Foreign Affairs, an office in which he negotiated the Portuguese entry in what is today the European Union.

The son of João Lopes Soares, a minister in the 1st republic, and Elisa Nobre Baptista, Mário Alberto Nobre Lopes Soares was born in Lisbon on 7 December 1924 and was a constant figure in the country’s public life both prior to the 25 April 1974 revolution and in the subsequent 40 years of Portuguese democracy.

He was a political prisoner and later he was an exile in São Tomé and Príncipe and France during the dictatorship.

Soares returned "on the people’s shoulders" to his country in 1974 to hold the posts of Foreign Minister in the first provisional governments, and to lead the 1st, 2nd and 9th constitutional government (1976-78 and 1983-85), until he was elected president of Portugal for two terms of office (1986-1996).

During one of his times in prison, in 1949, he married Maria de Jesus Barroso, who was then an actress and with whom he had two children ; Isabel, who is the director of Colégio Moderno, and João, who became mayor of Lisbon and is currently a Socialist MP.

In 1943, the graduate in Historical-Philosophical Science (1951) and Law (1957) clandestinely joined the Portuguese Communist party, which he was formally expelled from in 1950.

Since the founding of the PS in the German town of Bad Munstereifel on 19 April 1973, Mr Soares held the post of general secretary of the Portuguese socialists for 13 years until 1986.

After the April revolution, as the foreign minister in the first provisional governments, he was involved in the processes to recognise the fledgling Portuguese democracy and the decolonisation of Guinea-Bissau, Cape Verde, Angola, São Tomé and Príncipe and Mozambique and, on the domestic political stage, particularly in 1975, he was on the front line against the Communist-inspired PREC (Ongoing Revolutionary Process).

Later, as the prime minister of the 1st and 2nd constitutional governments, Mário Soares had to manage the return of thousands of citizens from the former colonies and the almost complete bankruptcy of the country, which involved the country turning to the IMF (International Monetary Fund) for the first time.

After 1977, it was by his hand that Portugal began the process to join what was then the European Economic Community (EEC), which was finalised on 12 June 1985, likewise during the period of a government he led (the 9th, with the "Central Block" PS/PSD (Social Democratic Party).

Shortly afterwards, in 1986, Mário Soares succeeded Ramalho Eanes in Belém, the presidential palace, defeating other left-wing candidates - Maria de Lurdes Pintassilgo and Salgado Zenha - and, in the only second round of presidential elections so far, the Christian Democrat Mr Freitas do Amaral. Mário Soares then became the first civilian president in democracy after a campaign that many people still remembered because of the slogan: "Soares é fixe" (Soares is cool).

Re-elected in 1991 for a second term of office in Belém – this one marked by political conflict with the prime minster at that time, Cavaco Silva – he was also a European Member of Parliament (1999) and stood again for the presidency (2006), losing to Cavaco Silva and he was even beaten in this ballot by fellow socialist Manuel Alegre.

Although he was formally distant from the front line of politics since 2006, Mário Soares still maintained regular public appearances, which were only interrupted for health reasons in the first two months of 2013.

In recent years, the former president was noted for his stinging criticisms of "neoliberalism", the functioning of the European Union, the centre-right PSD/CDS government of Pedro Passos Coelho, but also the previous socialist leader, António José Seguro.

After last May’s European elections, during the last internal crisis in the Socialist party, Mário Soares supported the victorious candidacy of the mayor of Lisbon and current general secretary, António Costa, from the outset.

More recently, he was the first Socialist personality to visit the former prime minister José Sócrates, on one occasion in Évora jail, when he made controversial declarations about the action of the judicial authorities in the case, and then later at home.