The veteran Welsh language campaigner and former president of Plaid Cymru Gwynfor Evans has died aged 92.
Mr Evans changed the face of British politics when he became Plaid's first MP in the 1966 Carmarthen by-election.
Fourteen years later he threatened to starve himself to death in the cause of Welsh language television, leading to the foundation of S4C.
Plaid president Dafydd Iwan said Wales might not even have been counted as a nation without him.
Mr Evans died on Thursday morning after having been ill for some time.
Mr Iwan said he would remain his party's spiritual leader.
He added: "It is impossible to underestimate Gwynfor's unique contribution to building Plaid Cymru into the party it is today."
First Minister Rhodri Morgan said Mr Evans had made a massive contribution to Welsh public life.
Gwynfor Evans was Plaid Cymru president for 36 years
Mr Morgan said while Mr Evans' relationships with Labour MPs "were not always positive," he was a "good and gentlemanly figure".
An adult learner of Welsh, Mr Evans was a teenager when Plaid Cymru was established in 1925, but he emerged as the party's president 20 years later - a position he held for 36 years.
Gwynfor Evans was born in Barry, south Wales, in 1912, but spent most of his life in Llangadog, Carmarthenshire.
Educated at the University of Wales, Aberystwyth, and then St John's College Oxford, he established a branch of Plaid Cymru while he was a student.
A committed Christian and pacifist, he refused to join the armed forces during World War II and was summoned to appear before a tribunal. He was unconditionally dismissed.
He was elected Plaid president in 1945 and would be at the centre of many of the party's triumphs and most hard-fought campaigns in the decades to come.
Mr Evans became the first Plaid voice in the Commons in 1966
In the 1950s, he fought but failed to establish a parliament for Wales. There was further defeat in his campaign to prevent Liverpool City Council flooding the Welsh-speaking Tryweryn valley near Bala to create a reservoir.
But the setbacks preceded a huge leap forward for his party and for the cause of nationalism in Wales.
In July 1966, he won the by-election in Carmarthen, called following the death of Labour MP, Dame Megan Lloyd George, the daughter of former Prime Minister David Lloyd George.
His victory was among the most unexpected in British political history, as Plaid Cymru won its first seat in Westminster.
Hundreds of supporters travelled to London to see him enter Parliament for the first time.
Speaking in the days following his election, he likened his position as a lone nationalist voice in the House of Commons to that of the Labour Party's first MP - Keir Hardie - more than 60 years earlier.
The Plaid president's starvation threat helped lead to S4C
Mr Evans said: "Keir Hardie was one man and he started something pretty big."
Three years later, Mr Evans lost his seat to Labour, but he returned to Westminster in 1974, this time with two more Plaid MPs - Dafydd Elis Thomas - now Lord Elis Thomas and presiding officer of the Welsh assembly - and Dafydd Wigley.
But in 1979, the year Margaret Thatcher came to power, he lost his seat and although he did not stand in an election again he kept himself busy in Welsh politics.
Having campaigned during the 1970s for the establishment of a Welsh language fourth television channel, he began a hunger strike in 1980, saying he would fast to death if the then Conservative government would not agree.
Against a background of other protests, the government gave in and S4C began broadcasting in 1982.
S4C's Chair Elan Closs Stephens said: "Gwynfor Evans realised the power of television to influence and change culture and language and he was determined that Welsh would have a proper place in the medium.
"He drew the world's attention with his dramatic stand."
The history of Wales was very important to Mr Evans, not only as a politician, but also as a Christian.
He wrote a number of books in both Welsh and English about Wales, his latest in 2001, Cymru o Hud in Welsh and Eternal Wales in English.
He also penned his autobiography, Bywyd Cymro (Life of a Welshman) in 1982 and in 1996, an English version, For the Sake of Wales.
By 1997, he had lived to see his dream being fulfilled, with a Yes vote in a referendum to set up of a Welsh assembly.
Fittingly, it all hinged on the final declaration in Carmarthen, which returned a narrow vote in favour.
Although he had graduated and trained to be a solicitor he worked as a commercial gardener in Llangadog until his retirement.
Mr Evans was married and had seven children, grand-children and great-grand-children.