Macaulay has seven brothers and sisters
The 43-year-old actor's father and mother Kit and Patricia Brentrup - who were together between 1974 and 1995 but never married - had six other kids, Shane, 47, the late Dakota, Kieran, 41, Quinn, 39, Christian, 36, and ‘Swarm’ star Rory, 34.
Kieran - who earned critical acclaim for his role as Roman Roy in the HBO series ‘Succession’ that concluded earlier this year - spoke about the constant “devastating” pain of losing his sister Dakota aged only 29 in a car accident.
He told the Hollywood Reporter: "I accepted at the time that this is going to be forever, and it's never going to be fine. It's always going to be devastating. I still weep about it out of nowhere. Something funny she did will pop in the head and make me laugh, and then I'm weeping."
Before getting together with the theatre producer, Kit welcomed a daughter, Jennifer Adamson - who passed away from a drug overdose in 2000 aged 29 - with his ex Adeena VanWagoner.