He speaks Italian - his wife is the Italian documentary producer Livia Giuggioli - knows Italy well and has three children of his own.
"You don't consciously try to equate your own life with your work, but there was a familiarity here, with ideas and feelings about fatherhood, that just resonated when we were doing it.
But talking about his private life is not something you'll catch Firth doing willingly.
"The thought of someone wanting to write about me and my life makes my blood run cold," he says. "Even if an article is brilliantly written, it always feels reductive and surely we all resist being defined. "I would prefer it if you exhumed my life after I've gone." More
