Tom Keneally
The central character is John Mitchel, a Presbyterian and a lawyer, an asthmatic and a reformer and an influential journalist who was born and raised in largely Catholic Ireland. You can look him up on Wikipedia, but Fanatic Heart makes better reading and arguably does more justice to the man and his wife Jenny.
Along with Mitchel the reader experiences Ireland during the potato famine, an Ireland under horrendous British rule. For his outspoken journalism and championship of Irish independence, Mitchel is sentenced to 14 years transportation: ‘The Treason Felony Act of 1848 had declared that it was a statutory offence punishable by up to 20 years’ imprisonment even to “imagine” let alone “compass or devise” that the British monarchy would ever lose sovereignty over Ireland, or any other part of Her Dominions.’
Thus, Mitchel is sent to Bermuda for a period before ending up in Tasmania, known at the time as Van Diemen’s Land. His treatment as a prisoner is surprisingly lenient compared to what one may imagine from the history books, perhaps because he is a political prisoner and not someone who has stolen a loaf of bread.