Sebastian Barry won the eighth £25,000 Walter Scott Prize for Historical Fiction, collecting his award at the 2017 Borders Book Festival.
He won the award for his American novel 'Days Without End'.
The author's previous novel, 'On Canaan's Side' won the prize in 2012.
The judges for the prize included writers and journalists and the festival director.
The Walter Scott Prize is awarded to UK, Irish or Commonwealth novels that are considered to be the "best" of the previous year, that are set more than sixty years ago.
It was founded in honour of Sir Walter Scott, who is considered to be one of the inventors of the historical novel genre.
Previous winners include Hilary Mantel, Andrea Levy, Tan Twan Eng, Robert Harris, John Spurling and Simon Mawer.