Jonathan was born in Dublin, Ireland on 27 July, 1977. When the actor was almost a year old, his family moved to County Cork, Ireland. When Jonathan was three years old, his father left and his mother had to take care of Jonathan and his 3 younger brothers.
Jonathan had an eventful childhood. He spent some time in an orphanage and at age 16, he was expelled from school. He was quite happy not to have to go to school any more and spent some of his time in a local pool hall. This is where he was discovered by Hubbard Casting. They were on the lookout for talent to appear in the David Puttnam production of "War of the Buttons" (1994) and asked Jonathan to audition. After auditioning for three days, he still did not get the part and Jonathan was ready to give up his aspirations to become an actor. However, he was quickly recalled to audition for a national campaign of ads for Knorr soup. Despite feeling embarrassed about the ad and the attention people paid him because of it, it helped gain him a part in a major film.
His first film role was a very small role in the film, "A Man of No Importance". He is simply credited as 'First Young Man.' His first lead role was in "The Disappearance of Finbar" in which he played the title character.
While he was visiting home in Cork, during a 6-month break in filming, he was contacted about appearing in "Michael Collins." He met its director, Neil Jordan, in Dublin and got to play the role of Collins' assassin.
From then on, Jonathan has been in constant demand. He appeared in such films as "Telling Lies in America," and "Match Point." The critics raved about some of his roles, especially about his performance as Brian Slade in "Velvet Goldmine," and as Steerpike in the British mini-series "Gormenghast."
Jonathan's talent is not limited to acting. He performed his own vocals in the film "Velvet Goldmine" and is included in the soundtrack.
Since 2007, he's received great reviews for his starring role as King Henry VIII in Showtime's The Tudors
Jonathan lives in London but also likes to spend time in Los Angeles where he has a home as well.