How the Count de Castelnau and his secret mistress fooled Melbourne with a web of lies

The French aristocrat who hid the salacious secret of a young mistress, illegitimate children and falsified birth certificates from Melbourne’s elite.

Francois Laporte, the Count de Castelnau, was French consul in Melbourne in the 1860s.

After a 19th-century French naturalist began an illicit love affair with the teen girl who nursed him back to health in Brazil, the couple reinvented themselves in Melbourne with a complex web of lies.

Having left his aristocratic wife behind in France, the Count de Castelnau and his lover, Carolina Fonceca, moved into adjoining houses in East Melbourne with a secret connecting door.

Their story of forbidden love is the subject of a new episode of the free In Black and White podcast on Australia’s forgotten characters:

Their story was uncovered by Melbourne author Caroline Petit, who attended an open house at an old mansion called Mayfield in Mordialloc in 2002, days before it was flattened to build a concrete plant.

Petit discovered the estate had been known locally as the home of the so-called “mad” Count Edward Fonceca, the illegitimate son of the Count and Madame Fonceca.

Her years of painstaking research from Paris to Melbourne uncovered a gripping tale of infidelity, a faked marriage, falsified birth certificates, an inheritance battle, and a horrific shooting death.

Melbourne in 1862, the year the Count de Castelnau arrived in Melbourne. Picture: State Library Victoria

When the Count, François Louis Laporte, an eminent naturalist, was appointed French consul in the 1860s in Melbourne, it posed a dilemma as he already had one son, Charles, with Carolina, and another on the way.

The couple created a story to hide the truth that the Count had been unfaithful to his wife and the children were illegitimate.

“Melbourne, I think, was a very conservative society at that time, especially in the upper echelons,” Petit says.

So Carolina was introduced to Melbourne’s elite as a grieving widow who wanted to make a new start in life after her husband, Mr “Fonceca”, died tragically.

Caroline Petit, author of The Natural History of Love.

The Natural History of Love book cover.

“Francois bought two adjoining terrace houses in East Melbourne, one was the French consul and his residence,” Petit says.

“Carolina and her two sons were living in the adjoining house, but the house had an interior secret door.

“And they really, I think, mostly lived together, with the caveat that the sons were not Francois’, but Francois was the, in quotes, ‘uncle’, and he was always to be addressed as ‘Uncle’, which must have been very disconcerting, especially for the older boy, Charles, who could look in the mirror, I am sure, and see he looked somewhat like his uncle.

“And I think that’s when the real trouble started.”

The family’s fascinating ups and downs was the inspiration for Petit’s new historical novel, called The Natural History of Love, out this week.

To learn more, listen to the interview with Caroline Petit in the In Black and White podcast on Apple Podcasts, Spotify or web.

See In Black & White in the Herald Sun newspaper Monday to Friday for more stories and photos from Victoria’s past.