Both sides of politics have finally found common ground, but it's taken 30 years.

Former Labor prime minister Bob Hawke and former Liberal prime minister Malcolm Fraser came together on Thursday night to launch the biography of Sir Ninian Stephen, who served as governor-general under both governments.

"I suppose you'd find it a bit strange for Malcolm and I to be on the same platform here," Mr Hawke said in a chuckle to those gathered in Melbourne at the book launch.

"Although these days," he added, "Malcolm appears on quite a range of platforms."

Mr Fraser, who raised a few eyebrows this year for endorsing Greens Senator Sarah Hanson-Young, took the quip in his stride.

"Bob Hawke is my successor, as a result of the one stupid decision I made," he said, referring to calling the 1983 snap election that sent the Liberals into opposition for 13 years.

Both leaders said Sir Ninian was a brilliant governor-general and his biography - spanning careers from High Court judge to international diplomat - details a truly remarkable but humble Australian.

Sir Ninian, now 90, said it was a privilege to have served under both leaders.

"Mr Fraser appointed me, Mr Hawke extended me," he said.

* A Fortunate Voyager: The Life of Ninian Stephen, by Philip Ayres, is published by Melbourne University Publishing, rrp $59.99.