Charles Fraser, who has been head of the homelessness charity St Mungo’s since 1994, has announced that he will step down as chief executive in April.
Fraser has been with the charity since joining on a temporary contract in 1980 as a project worker at a hostel in central London.
He said he did not know what he would do after leaving St Mungo’s but would take some time off before considering his next steps.
"It has been an enormous privilege to have led an organisation that, I like to believe, has made a real difference to the lives of so many extremely disadvantaged people," said Fraser. "I count myself fortunate to have known and worked with so many able and dedicated people, both in St Mungo’s and outside.
"It now feels right, however, to let someone else steer St Mungo’s through its next phase of development and impact."
He was awarded a CBE for services to homeless people in the Queen’s birthday honours list in June 2007.
Paul Doe, chair of St Mungo’s, paid tribute to Fraser’s leadership. "He has steered St Mungo’s from being a £10m charity employing about 350 staff in 1994 to one with an annual turnover of £54m, employing about 900 staff," he said.
The charity said that Fraser would continue to take part in other groups he is involved in, including the National Inclusion Health Board and the National Third Sector Learning & Skills Implementation Board.