The most senior official in a Priory is the Prior (in Australia this has traditionally been the Governor-General). The Chancellor is the deputy of the Prior. In practice, all of the leadership functions are delegated to the Chancellor, who exercises these responsibilities as the Chair of a national Board of Directors.

Biographical information about the first seven Australian Chancellors can be found in the article below. Since this article was written, two more Chancellors have been appointed (Prof Mark Compton, and Mr Cameron Oxley).
Howie-Willis I. The Chancellors: The seven distinguished Australians who have led the Australian Priory of the Order of St John since 1946. St John History, 2011; 11: 57-64.

In Australia, we have a tradition that each outgoing Chancellor has their portrait painted – these are shown below. Click on each image for a closer look.

Professor Mark R Compton AM GCStJ
2014-2019
Artist: Evert Ploeg, oil on canvas
Dr Neil R Conn AO GCStJ
2007-2014
Artist: Evert Ploeg; oil on canvas
Professor Villis R Marshall AC GCStJ
1999-2007
Artist: Evert Ploeg; oil on canvas
Mr Peter FG Henderson AC KStJ
1996-1999
Artist:
Sir Guy SM Green AC KBE KStJ
1991-1995
Artist:
Sir John M Young KCMG GCStJ
1982-1991
Artist:
(image to come)
Sir George GL Stening Kt GCStJ
1961-1982
Artist: Graeme Inson
Sir Hugh RG Poate KVO GCStJ
1946-1961
Artist: Joshua Smith, oil on canvas