A humorous book about two big names in Australia's theatre and film history has won the nation's richest biography award.
The Two Frank Thrings by Peter Fitzpatrick held off strong competition from 71 entries to pick up the $25,000 National Biography Award, seen as the most prestigious of Australian biography prizes.
Frank Thring senior, born in 1882, started his career as a sideshow conjurer and went on to become Australia's largest film entrepreneur of the early 1930s. He ran Hoyts cinemas, founded Melbourne's Efftee films, established the Australia-wide chain of luxurious Regent theatres and opened Melbourne radio station 3XY.
His son of the same name, born in 1926, was a flamboyant actor, local television personality and international film star.
Both men were well known but cleverly managed to conceal their "real" selves, Fitzpatrick told AAP at the State Library of NSW on Monday.
"The detective work really drove this project.
"So much of the information was difficult to access, if not impossible."
Thring senior, who died when his son was 10, was a reserved man who never correctly filled out a birth, death or marriage certificate and promoted riddles about his background, Fitzpatrick says.
His son, quite the opposite, was a "crazy, self-parodist" who talked constantly about himself but revealed very little of substance.
"They were both in their own ways very, very private."
The chair of the judging panel, Dr Bernadette Brennan, described the book as a "brilliant, dual linked biography of a father and son who, together and individually, distinctively marked a century of Australian performing arts in film and theatre".
The other short-listed authors for the prize - James Button (Speechless: A Year in my Father's Business), Robert Drewe (Montebello: A Memoir), Jenny Hocking (Gough Whitlam: His Time) and Rachel Robertson (Reaching One Thousand) - each received $1000.
Fitzpatrick, 68, honorary professor of performing arts at Monash University, initially became interested in Thring Senior.
"I thought it was an untold story that we should know more about.
"I was intrigued by him, he staged Collits' Inn in Melbourne in 1933, Australia's first locally written major musical play.
"It's quite a dated show but it was an extraordinary thing in its time.
"And then there was this father and son that looked so alike but their personal styles and the shapes of their lives were completely contrasting."
Fitzpatrick is not a stranger to writing dual biographies. He published Pioneer Players: The Lives of Louis and Hilda Esson in 1995.
* The Two Frank Thrings by Peter Fitzpatrick is published by Monash University Publishing, rrp $49.95.