Hundreds of people have gathered in Derry to accompany the body of Martin McGuinness on his final journey home.
Crowds braved snow and sleet in Mr McGuinness's native Derry to accompany his coffin, draped in an Irish tricolour, from the funeral parlour to his home in the Bogside.
Mr McGuinness, 66, died during the night at Derry's Altnagelvin Hospital with his family by his bedside.
Sinn Fein said it is "with deep regret and sadness that we have learnt of the death of our friend and comrade Martin McGuinness who passed away in Derry during the night. He will be sorely missed by all who knew him."
The Queen is to write to the widow of former deputy First Minister Martin McGuinness following his death.
A Buckingham Palace spokeswoman confirmed to the Belfast Telegraph a private message will be conveyed to Mr McGuinness's wife, Bernie.
He had met the Queen on a number of occasions.
The two shook hands in 2012 at a charity event in Belfast at the Lyric theatre.
Asked what he thought of the meeting, Mr McGuinness quipped: "I'm still a republican."
After a meeting in Hillsborough Castle last June, Mr McGuinness greeted the Queen by asking if she was well. She replied: "Well, I’m still alive."
Mr McGuinness will be laid to rest on Thursday. His funeral will leave his home on Westland Terrace in the city on Thursday at 1.20pm on Thursday, with Requiem Mass in St Columba’s Church Longtower at 2pm.
His remains will be interred in The City Cemetery afterwards.
The tricolour over Leinster House will fly at half-mast on Thursday in honour of Martin McGuinness.
In a statement Ceann Comhairle, Seán Ó Fearghaíl said Mr McGuinness was "an iconic figure who made the journey from conflict to peace, playing a key role in in bringing about and maintaining the peace process and the Good Friday Agreement".
"He was a capable, hard-working and determined man who showed a willingness to compromise and reach out to others in a spirit of reconciliation."
Political leaders from both side of the border have remembered him as a man who embarked on a "remarkable journey" from his days as an IRA commander to an architect of peace in Northern Ireland.
He had been diagnosed with a rare heart disease in December.
In January Mr McGuinness stepped down as deputy First Minister amid the so-called cash-for-ash scandal which saw DUP leader Arlene Foster come under mounting pressure to resign.
Mr McGuinness’s resignation triggered a snap election which changed the landscape in Stormont.
Before stepping down he was forced to withdraw from an official trip alongside Ms Foster on medical advice.
Delivering his farewell speech he looked pale and gaunt.
Mr McGuinness emerged as one of the major player’s in Northern Ireland’s peace process and became Sinn Fein’s most recognisable face after Gerry Adams.
Mr Guinness was appointed Deputy First Minister of Northern Ireland on May 8 2007, with DUP leader Ian Paisley becoming First Minister, following the St Andrews Agreement and the Assembly election.
In June 2008 he was reappointed as Deputy First Minister to serve alongside Peter Robinson, who succeeded Mr Paisley as First Minister.
Mr McGuinness has always acknowledged his IRA past.
In 1972, at the age of 21, he was second-in-command of the IRA in Derry, a position he held at the time of Bloody Sunday, when 14 civil rights protesters were killed in the city by soldiers with the 1st Battalion, Parachute Regiment.
The following year he was convicted by the Republic of Ireland's Special Criminal Court after being arrested near a car containing explosives and ammunition.
After his release, and another conviction in the Republic for IRA membership, he became increasingly prominent in Sinn Féin and was first elected to parliament in 1982.
He is survived by his wife Bernie, and their four children.
Former US President Bill Clinton has paid tribute to Martin McGuinness describing him as “calm, courageous, and direct”.
In a statement Mr Clinton said he and his wife Hillary were saddened to learn of Mr McGuiness’s death.
“As Sinn Féin’s chief negotiator, his integrity and willingness to engage in principled compromise were invaluable in reaching the Good Friday Agreement.
“In the years that followed, he played an even more important role in ensuring that the peace would last – personally overseeing the arms decommissioning, joining the new government as the first Education Minister, and later serving as Deputy First Minister, and doing it all with a sense of humour and fairness that inspired both his friends and former foes,” he said.
Mr Clinton added that his last memory of Mr McGuinness "will be the pride he took in his efforts to improved disadvantaged schools in Unionist and Protestant communities".
“He believed in a shared future, and refused to live in the past, a lesson all of us who remain should learn and live by.”
Sinn Féin's President Gerry Adams led tributes to Mr McGuinness this morning.
Speaking on RTÉ'S Radio One's Morning Ireland he reflected on the passing of his colleague.
"We wouldn't be where we are without him," he said.
"Martin led the IRA when there was a war but Martin led the IRA into peace... he genuinely believed in reconciliation, even when it made people uncomfortable," he added.
"I am very sad this morning... he will be missed," he added.
Asked to reflect on his journey from militant republican to a broker of peace he said:
"It was a long time in the making.
"Martin McGuinness never went to war, it came to him. It came to his streets.. his community," he added.
In an earlier statement he said:
“Throughout his life Martin showed great determination, dignity and humility and it was no different during his short illness.
“He was a passionate republican who worked tirelessly for peace and reconciliation and for the re-unification of his country. But above all he loved his family and the people of Derry and he was immensely proud of both."
President Michael D Higgins has remembered his " immense contribution to the advancement of peace and reconciliation in Northern Ireland".
"A contribution which has rightly been recognised across all shades of opinion," he said.
"As a political colleague of many years, and having participated together in the Presidential election campaign of 2011 that brought us all over Ireland, Sabina and I have appreciated both Martin McGuinness’ warmth and his unfailing courtesy."
Taoiseach Enda Kenny has also released a statement to pay tribute to Mr McGuinness.
"Martin will always be remembered for the remarkable political journey that he undertook in his lifetime. Not only did Martin come to believe that peace must prevail, he committed himself to working tirelessly to that end.
"Martin was one of the chief architects of the Good Friday Agreement and he worked resolutely in the years that followed it in pursuit of its full implementation. I got to know Martin well in recent years, including through our working together in the North South Ministerial Council. His commitment to securing enduring peace and prosperity for all of the people of Northern Ireland was unwavering throughout this time. He strove to make Northern Ireland a better place for everyone, regardless of background or tradition."
Archbishop of Ireland Eamon Martin has also joined those paying tribute.
"People like Martin McGuinness have made an immense contribution to sustaining peace by reaching out a hand of friendship and reconciliation and being prepared to model alternatives to dispute and division," he said.
"Martin was ambitious for peace. He knew that peace was worth striving for and was within reach in his life time."
British Prime Minister Theresa May said Martin McGuinness "played a defining role in leading the Republican movement away from violence",
"While I can never condone the path he took in the earlier part of his life, Martin McGuinness ultimately played a defining role in leading the Republican movement away from violence," she said in a statement.
"In doing so, he made an essential and historic contribution to the extraordinary journey of Northern Ireland from conflict to peace.
"While we certainly didn't always see eye to eye, even in later years, as deputy first minister for nearly a decade he was one of the pioneers of implementing cross-community power-sharing in Northern Ireland. He understood both its fragility and its precious significance and played a vital part in helping to find a way through many difficult moments.
"At the heart of it all was his profound optimism for the future of Northern Ireland - and I believe we should all hold fast to that optimism today."
Former SDLP leader John Hume and his wife Pat have said Mr McGuinness “left an indelible print on politics in Ireland”.
“Our starting points on the approach to finding a solution to the divisions on this island were very different but there can be no doubt Martin was deeply committed to the agreed Ireland of the Good Friday Agreement and its power sharing institutions.
“He played a very important role in our peace process and his courageous, generous and gracious gestures as deputy First Minister were offered in a spirit of reconciliation and peace building.
“Our deepest condolences go to his wife Bernie, their children Fiachra, Emmet, Grainne, Fionnuala and the wider family circle,” they said in a statement.
Former PM Tony Blair, who was in Number 10 when the Good Friday Agreement was signed in 1998 said he will remember Mr McGuinness with "gratitude".
He said: "I grew up watching and hearing about the Martin McGuinness who was a leading member of the IRA engaged in armed struggle.
"I came to know the Martin McGuinness who set aside that armed struggle in favour of making peace. There will be some who cannot forget the bitter legacy of the war. And for those who lost loved ones in it that is completely understandable.
"But for those of us able finally to bring about the Northern Ireland peace agreement, we know we could never have done it without Martin's leadership, courage and quiet insistence that the past should not define the future."
Mr Blair said he got to know the Sinn Fein politician well during the "arduous" negotiations and "by the time that extraordinary day arrived in 2007 after almost a decade of hard work where we could witness the - to my generation - incredible sight of he and Ian Paisley sitting down together in government, the transition of Martin to reconciliator was complete".
The former prime minister said "whatever the past, the Martin I knew was a thoughtful, reflective and committed individual", adding that he showed "no shortage of determined opposition to those who wanted to carry on the war".
Former Taoiseach Bertie Ahern also expressed his condolences for Mr McGuinness's family.
"Ireland today has lost a great leader. It is with deep regret and sorrow that I have learned of the death of the former deputy First Minister of Northern Ireland. I wish to express my sincere sympathy to his wife Bernie, his extended family, and all those close to him," he said in a statment.
"Martin McGuinness was a pivotal figure in Irish republicanism for over 40 years. He made a journey, if not without historical precedent, then certainly without equal in modern Ireland. It began for a very young man in pursuit of violent struggle. It ended only weeks before his death, after years in office, spent strengthening the peace he worked for and to which his leadership was essential."
"He was a critical part of changing the course of history toward the path of peace in Northern Ireland," he added.
Another former Taoiseach John Bruton said in a statement that a genuine political reconciliation in Northern Ireland has yet to occur.
“I am very sorry to hear of the death of Martin McGuinness at such a young age.
“Notwithstanding our profound political differences, I always found him to be a very friendly person and easy to talk to.
“The good and warm personal relationship he developed with Ian Paisley set a very good example. But it has yet to be followed by a genuine political reconciliation between the two communities they represented."
“It is sad that Martin will not be around to complete the important task he undertook."
Current leader of Fianna Fáil Michael Martin said Mr McGuinness "was deeply committed to reconciliation".
“As a man, he possessed great humility, and was very personable. His work in the Peace Process will undoubtedly inspire others to follow his legacy in continuing to build stronger bridges between both traditions on this island," he said.
DUP leader Arlene Foster also paid tribute to the Sinn Féin stalwart.
Democratic Unionist Party (DUP) leader Arlene Foster said his death "will come as a shock to many people".
"History will record differing views and opinions on the role of Martin McGuinness played throughout the recent and not so recent past but history will also show that his contribution to the political and peace process was significant," she said.
"He served the people of Northern Ireland as deputy first minister for nearly a decade and was pivotal in bringing the republican movement towards a position of using peaceful and democratic means.
"While our differing backgrounds and life experiences inevitably meant there was much to separate us, we shared a deep desire to see the devolved institutions working to achieve positive results for everyone.
"I know that he believed that the institutions were the basis for building stability."
Ms Foster also confirmed that she had been in contact with him before his death to RTÉ's News at One.
"He said he appreciated that I had been in touch."
Lord Peter Mandelson described him as a "great soldier".
"While we had differing backgrounds, we shared a deep desire to achieve positive results for everyone.
"We've lost a great soldier but at the same time, I think that his death will serve to remind people of what we have left in the past, the importance of what has been created and not putting it in jeopardy."
Sinn Féin's North Belfast MLA Gerry Kelly said Mr McGuinness was a "political gent".
"I have known Martin for decades. He had a great sense of humour, he was absolutely committed and he wanted to make a difference in peoples lives.
"I think I would describe him as an Irish political gent. I have travelled to conflict areas in the world and one of the things people want to continuously find out from us is how do you move from conflict into a peace process and then into politics to make a difference in peoples lives, and that is what his legacy will be."
SDLP Leader Colum Eastwood said "the Derry man’s remarkable journey from paramilitarism to peace was a hallmark of the transformative effect of the peace process".
“History will record his political career as a journey – one born in a tradition of violence but, in a testament to Martin’s character, that arrived at his true calling in politics, people and the art of persuasion," he said.
The son of Ian Paisley, Kyle, released a statement on Twitter:
"Very sorry to hear about the passing of Martin McGuinness. Look back with pleasure on the remarkable year he and my father spent in office together and the great good they did together.
"Will never forget his ongoing care for my father in his ill health," he said.
Former Northern Ireland secretary Peter Hain has also praised Mr McGuinness' transformation from IRA chief to political leader.
"He had the grassroots credibility of a republican leader and former IRA commander, that could enable him, along with Gerry Adams, to take his followers, to take republicans, from the past of terror and horror into a democratic future, which is what he did," he said.
Minister for Foreign Affairs and Trade, Charlie Flanagan, speaking to RTE's Morning Ireland programme, said Mr McGuinness was a man who had travelled a large journey with great conviction:
"We've lost somebody who embarked on a really significant personal journey from militant republican to a Deputy First Minister in Northern Ireland and who made a great contribution to the Good Friday Agreement," he said.
"I'd like to acknowledge his journey and I'd like to acknowledge his contribution to peace and particularly his contribution over recent years and the manner in which he always showed he a willingness to stretch himself in contribution to peace and stability," he added.
On a personal level he also got to know Mr McGuinness and said he spoke about the threats that the former IRA commander had to withstand, in his pursuit of peace he said.
The Fine Gael TD acknowledged there is much about Mr McGuinness that people may never know, but he was keen to remember him as an "architect of peace".
Independent Dublin City Councillor and former Lord Mayor of Dublin Christy Burke today paid tribute to Martin McGuinness, saying he was a "true son of Ireland".
"I was saddened this morning to hear that Martin had passed away. He was an honest broker, a soldier and a peacemaker and he will be greatly missed," he said.
"He was full of dignity and integrity. Ireland has lost a true son. Martin was a passionate individual about whatever it was he put his hand and heart to," he added.
Christy Burke is a Republican who sided with the IRA in the 1970 split in Sinn Fein and the IRA and served two terms in Portlaoise Prison on IRA membership charges in the 1970s.
He has requested a a book of condolences to be opened in the city and is awaiting a reply.
Current Lord Mayor, Brendan Carr, said the flag on the Mansion House will fly at half mast on the day of the funeral, as he expressed condolences to his the family of Martin McGuinness.
Former President Mary McAleese said it was important to remember the context of Mr McGuinness' upbringing, which was ear-marked by poverty and a divided community.
"Out of that he made a choice as a young man to take a part path and that pathway was to resist with the use of violence," she told Seán O'Rourke on RTÉ Radio One.
He was "dedicated to the betterment of his community and who eventually was persuaded that the best way forward was not through the use of violence," she said.
"It says something about the leadership qualities of him as a person that he was able to bring the IRA on board with him."
She said he visited with Mr McGuinness in his final days and that he seemed very much at peace with himself.
Speaking on the same programme Mary Lou McDonald, deputy leader of Sinn Féin, also reflected on what she has learned from him as a colleague.
"We have indeed lost a leader for very many people, a hero not just of Republican struggle but a hero of peace-making as well," she said.
"Martin walked his life's journey always with a sense of purpose and determination," she added.
Additional reporting by Press Association