The man who was chosen by young people to champion their causes in Northern Ireland has died.
Nigel Williams was appointed children's commissioner in 2003
Nigel Williams, a father of four, was selected as Northern Ireland's Commissioner for Children and Young People (NICCY) in June 2003.
Among his achievements as commissioner were the completion of a large investigation into vetting in Northern Ireland.
Mr Williams died on Tuesday at his home in Glenarm, County Antrim.
Chief Executive of NICCY, Barney McNeany, who is currently acting commissioner said: "Nigel battled long and hard against this illness, continuing to contribute to the work of NICCY despite often significant obstacles.
"We offer our sincere condolences to his wife, Heather, and all his family.
"The staff of NICCY and his many friends here - in particular the NICCY Youth Panel - will greatly miss his inspiring leadership and vitality."
Prior to working with NICCY, Mr Williams, who is originally from Limavady, founded the charity, Childnet International, in 1995.
He was also a board member of the Internet Watch Foundation, and of the Internet Content Rating Association and was appointed by the Home Secretary in 2001 to the Task Force on Child Protection on the Internet.
Secretary of State Peter Hain said he extended sincere sympathy to the family of Mr Williams on behalf of the government.
"Nigel's appeal to children and young people was immediately evident when those involved in his appointment gave him an overwhelming seal of approval. He was a real children's champion," he said.
"At one of my first meetings with the commissioner, his enthusiasm, dedication and solid determination were palpable."
The NI divisional director of the National Society for the Prevention of Cruelty to Children (NSPCC), Ian Elliott, said Northern Ireland had been "robbed of a great advocate for children".
"Even though he has been in post for a limited period, Nigel has achieved a great deal and has left a wonderful legacy on which to build," Mr Elliott said.
Barnardo's NI director Lynda Wilson said: "The commissioner's post was designed to be a champion for children and there is no doubt that Nigel Williams took on this role with great gusto and enthusiasm.
"It was also clear that he cared deeply about the rights of children and young people and their right to be heard and a fitting tribute to him will be that we all continue our efforts to make sure that all children have a stake in our society."
Sinn Fein assembly member Sue Ramsey said: "Nigel brought an energy and passion and a deep commitment to his work.
"His leadership will be sadly missed by everyone who had the opportunity to work with him and I am sure that many, many people will share this loss with his family."
DUP assembly member Arlene Foster said Mr Williams would be "sadly missed".
"Nigel certainly brought a lot of energy to his post and will be sadly missed by all who worked with him," she said.
"As a party, we extend our deepest sympathy to his wife and family at this difficult time."
Geraldine McAteer of the West Belfast Partnership said Mr Williams would be remembered "as a champion for the rights of all our children".
"His commitment and dedication to young people here was remarkable, and our partnership is deeply saddened to hear of his passing," she said.