A former businessman and teacher, FitzHerbert joined the Directory of Social Change in 1984, after a period at the NCVO. He remained involved with the training and publishing work of the DSC right up to his death, campaigning on behalf of small charities and leading calls for greater openness in the sector as a whole.
Debra Allcock Tyler, chief executive of the Directory of Social Change, said: "The organisation is riven with shock and distress. Luke was the touchstone of the DSC.
"He was our shining example of the need to stick your neck out on behalf of others, regardless of the personal criticisms that displaying that courage might incur. He stood for principle-based arguments, the need to challenge those who were in positions of privilege and power and continually remind them of their duty to wider society.
"We can honour Luke only by doing our best to continue his work with the same zeal and commitment to independence. We will miss this maverick, passionate, challenging and charming man desperately, and our hearts go out to his family."
FitzHerbert was a strong advocate of the cause of small charities and a frequent critic of the Charity Commission for over-regulation and an obstructive registration process.
His trenchant and original thinking won him the lifetime achievement title when the Third Sector Excellence Awards were first held in 2005.
He was recognised for being a free spirit who drove forward important issues such as transparency.
Geraldine Peacock, former chair of the commission, lauded his role as the "self-appointed watchdog" of the sector.
"I was fond of him even though he was quite critical of me," she said. "He did it in a gentlemanly manner. He was a cross between Don Quixote and an English gent."
Stuart Etherington, chief executive of the NCVO, described FitzHerbert as a champion of the smaller organisation.
"His work helped many charities develop and thrive," said Etherington.
"He was a thorn in the side of the powerful and was never afraid to put his head above the parapet on the policy issues of the day. He was stubborn in defence of the powerless. The sector is the weaker for his loss."
Michael Brophy, former chief executive of CAF, who went to school with FitzHerbert and met him again in the 1980s when both were working in the voluntary sector, said he was "fearless and generous in equal measure".
Campbell Robb, director general of the Office of the Third Sector in the Cabinet Office, said FitzHerbert "embodied everything good about the voluntary sector".
FitzHerbert's past and present colleagues at the DSC paid their own tributes.
Faisel Rahman, managing director of ethical lender Fair Finance, said: "Luke was one of the few truly radical people I have ever met."
Susan Forrester, the former editor of the DSC's Funding for Change, said: "He was fearless, and thoroughly enjoyed a good fight. He breathed fresh air into the closeted world of fundraising."
Details of a planned memorial service will be published in due course.
He said it
'Public service delivery on contract by non-profits and mutuals is not what people understand by charity - the lustre that the word charity enjoys is at risk' - March 2006
'Many trusts see themselves as private institutions. These are rich people not used to having their financial dealings talked about by the plebs' - December 2003
'Isn't failure to rebel against what is bad collusion in keeping it bad?' - November 2003
'A few years ago the commission used to reject one in 10 of all new charitable applications. It now rejects one in three, a change of which it appears to be proud' - April 2001.