The portraits were created 45 years ago by Nick and Cally Trench and depict how each one viewed the other.
The Siblings Cannot Agree exhibition at the Middleton Cheney gallery located in Chenderit School, brings together a range of portraits and self-portraits of themselves spanning five decades.
The work features depictions of full faces, isolated features, hands and feet dating back to their teenage years in London through later adult life and to the present day.
Cally said: “The idea for this exhibition came from rediscovering two drawings from November 1970, one by Nick of me and one by me of Nick.
“It was 47 years since we’d made them, but the character of each was still recognisable in the artists we’d become. It has prompted us to pick up where we left off.”
She added: “In using each other as artistic raw material over many years, we respect each other’s work but we simply behave and express ourselves differently.”
Cally uses a variety of media including pencil, ink, oil and film pieces and concentrates on movement of form and human physicality.
Nick, on the other hand has a differing inspiration for his portraits and self representations.
He said: “I explore figures in different environments or treat them in different ways.
“Sometimes the figure may disappear entirely, perhaps it merges into surroundings or disappears behind them.”
The two pencil portraits from 1970, which served as inspiration will sit side-by-side to open the display as an illustration of the siblings’ highly disparate artistic expressions.
It is only the second time the brother and sister have teamed up for an exhibition which will begin on Sunday, September 16 with an opening event between 3pm and 6pm.
Tom Christy, head of Chenderit School’s art department, said: “I love the way the exhibition encourages the viewer to reassess their own sibling relationships as well as posing more general questions to do with identity and self.
“Having the show in a gallery linked to a school makes these questions even more pertinent. Our siblings, whether we like it or not, have a great deal of influence and impact on who we each become.”