Thousands descended on Londonderry to mark 50 years since the Duke Street Civil Rights movement march.
Half a century ago and with the support of the Northern Ireland Civil Rights Association (NICRA), protesters took to the city's streets over the perceived injustices against Catholics. The march had been banned by the then Northern Ireland government but went ahead in defiance.
As those taking part met police lines, officers batons and water cannon to break up the march with dramatic images broadcast around the world.
The events of Saturday, October 5, 1968 were a watershed in the history of Northern Ireland with events on that day widely seen as the crucible of the Troubles.
NICRA demanded an end to gerrymandering and discrimination and called for "one man, one vote".
The campaign signalled the end of unionist majority rule at Stormont. It also changed the face of nationalist politics and put the story of Northern Ireland to a global audience.
Irish president Michael D Higgins said it was an honour to take part in the anniversary events.
He said the march "galvanised" the movement for civil rights in Ireland.
"As President of Ireland, it is a great honour to join you all in commemorating one of the great movements for justice and civic equality on our island, the Northern Ireland Civil Rights Movement, on this, the 50th anniversary of one of the most important events in the history of our island in the 20th century, the Civil Rights march that took place in this great city on the 5th of October, 1968," he said.
He paid tribute to the vision of former SDLP leader and Nobel laureate John Hume. He said he was concerned his contribution and "his dogged persistence through the dark twilight years of the Troubles, might be eclipsed amidst the disputations of the contemporary moment."
"Perhaps less recognised today is his role in persuading, even forcing, the administrative and political elite of the southern State to renew their engagement with Northern Ireland, and to put aside sometimes unrealistic and inflammatory rhetoric. We all no doubt remember the deep hostility that John Hume evinced by taking the courageous step of opening a dialogue with Sinn Fein in 1988.
"As we assemble today let us, above all, recall the vision of John Hume, so rooted in the experience of the Civil Rights Movement. A vision of a shared Ireland, one that recognises the unionist and nationalist traditions, one that is capable of reconciling communities, one that, North and South, preserves human dignity and vindicates and expands fundamental human rights – in the economic, cultural and social spheres.
"If we remain true to that vision, we can not only sustain peace on our island, but can, together, confront the shared challenges of the future with confidence and courage.”