The funeral of Martin McGuinness has taken place in Derry with thousands of mourners joining politicians and dignitaries from around the world paying tribute.
There was a round of applause inside the church as DUP leader Arlene Foster took her seat.
The symbolism of the leader of unionism attending a former IRA man's funeral is highly significant - even more so in Mrs Foster's case, as her father survived an IRA murder bid during the Troubles and she herself was on a school bus caught up in an IRA bombing as a child.
Mrs Foster, who had been undecided about attending until last night, arrived for Requiem Mass which began at 2pm.
Mr McGuinness's wife Bernie carried the coffin as it made its way along part of the route the civil rights march took on Bloody Sunday in 1972.
The procession then made its way past the iconic Free Derry Wall mural.
The crowd broke into applause as family members slowly carried the coffin along the street.
A piper continued to play as the coffin was carried down the hill, through the former first minister's beloved city.
The funeral procession stopped and the coffin was then handed over to be carried by members of Sinn Fein leadership, including Gerry Adams and Michelle O'Neill.
After a slow walk through the streets of Derry, the funeral procession arrived at the church an hour after leaving the family home.
Thousands gathered outside the church broke into applause as the procession entered church grounds.
Bill Clinton's full speech at the funeral of Martin McGuinness https://t.co/9poLXrLATi — RTÉ News (@rtenews) March 23, 2017
Former US President Bill Clinton arrived to the church a round of applause from gathered crowds. Mr Clinton was the last person to speak at the funeral. He said: "I came to treasure every minute I spent with Martin McGuinness."
He added that to honour Mr McGuinness would be to finish the job of peace that his friend at started.
Just before the mass got under way Sinn Fein president Gerry Adams introduced President Clinton to Mr McGuinness's widow Bernie and children.
Former first minister Peter Robinson and former economy minister Simon Hamilton were at the church.
As was PSNI Chief Constable George Hamilton.
President Michael D Higgins and his predecessor Mary McAleese were also at the Requiem Mass for the Sinn Fein veteran, as was Taoiseach Enda Kenny.
DUP Leader Arlene Foster and her predecessor Peter Robinson have arrived for the funeral of Martin McGuinness. Big moment. pic.twitter.com/29P8LqL51c— Richard Chambers (@newschambers) March 23, 2017
Bishop Donal McKeown, Bishop of Derry, opened the service by welcoming dignitaries, public figures and politicians from Ireland, Britain and the US.
He then turned to the McGuinness family and said: "For you this is not the funeral of a public figure.
"This is a funeral of a husband, father and a grandfather and our first thoughts are inevitably with you."
Bishop McKeown noted the applause inside St Columba's when some politicians had arrived ahead of Mr McGuinness's remains, including for Mrs Foster.
And he thanked those who had been involved in securing the Good Friday Agreement who travelled for the mass, including from within Northern Ireland and the Republic and Britain and the US.
"It's a tribute to those who didn't just talk the talk but walked the walk of implementing the Good Friday Agreement that all three of those strands are so well represented here," he told mourners.
More than an hour before the service, big crowds began to gather in front of Mr McGuinness's house in Derry ahead of the funeral. Sinn Féin's Gerry Adams was seen comforting mourners.
Mr McGuinness died from a rare heart condition on Tuesday aged 66.
During the church service, Fr Canny revealed having many conversations with Mr McGuinness in which the Sinn Fein veteran said he knew only too well how many people struggled with his IRA past.
"Republicans were not blameless, and many people right across the community find it difficult to forgive and impossible to forget," he said.
"By any standards, Martin McGuinness was a remarkable man and his life was a remarkable journey. The values he had, the principles he championed are still very much alive.
"On that journey many years ago, Martin realised that the time for peace had come and he pursued the peace process with relentless energy for the rest of his days, until illness finally struck him down.
"In the course of that journey he encountered many obstacles but he remained resolute. In conversation he often repeated that there was no other way, we had to continually work for the building of peace and a better future for all.
"Despite many setbacks he never became disheartened."
Huge crowds gathering at Martin McGuinness's home for start of his funeral in less than an hour. pic.twitter.com/fIO8asxM8g— Ivan Little (@BigIvanLittle) March 23, 2017
Hours before Mr McGuinness's funeral at St Columba's Church Longtower this afternoon, the same chapel witnessed the funeral of the popular captain of Derry City FC Ryan McBride (27) who was found dead in his bed on Sunday.
Mr McGuinness's death came in the midst of a political crisis at Stormont, with talks ongoing to form a new powersharing executive following the acrimonious collapse of the last administration.
Martin McGuinness' funeral cortege will pass Free Derry Corner and the Bloody Sunday memorial on the way to the Longtower Church today— Allison Morris (@AllisonMorris1) March 23, 2017
Though thousands of supporters have lauded the legacy of Mr McGuinness, his death has drawn a very different response from many victims of the IRA, with some bereaved relatives not prepared to forgive him for his paramilitary past.
On Wednesday, political leaders at Westminster and Belfast commended his contribution to the peace process.
British Prime Minister Theresa May told parliament she could never condone the ex-IRA commander's violent past but she credited his "indispensable" role in moving the Republican movement away from armed conflict.
At a special session of the Stormont Assembly, Mr McGuinness's Sinn Fein successor Michelle O'Neill paid an emotional tribute while Mrs Foster acknowledged that Northern Ireland would "never see his like again".
Mrs O'Neill told the Assembly her heart was broken yet bursting with pride.
Just in: President Obama statement on death of Martin McGuinness pic.twitter.com/JO94gd9Zaf— Niall Stanage (@NiallStanage) March 22, 2017
"The legacy that Martin wished was for a better future based on equality and measured by the joy and laughter of all of our children," she said.
"So, on behalf of Sinn Fein I rededicate our party to completing his life's work and to living through his legacy."
Mrs Foster said Mr McGuinness's legacy was "complex and challenging".
"Things have fundamentally changed since I was growing up in the 70s and 80s and changed immeasurably for the better and Martin McGuinness did play a role which I will always condemn in the 70s and 80s, but I also have to acknowledge the role that he played over this last decade and more in government in Northern Ireland," she said.
Mr McGuinness completed an extraordinary political journey from an IRA leader in Derry to sharing power and a remarkable friendship with his erstwhile foe, DUP leader Dr Ian Paisley.
He also struck up a warm relationship with the Queen, whom he praised for her contribution to peace. She is to send a personal message to Mr McGuinness's family.
Mr McGuinness's last major act as a politician was to pull down the powersharing executive at Stormont when he resigned as deputy first minister in January in protest at the DUP's handling of a green energy scandal.