The First Trial by Combat of Tyrion Lannister is a key event in the build-up to the War of the Five Kings. Tyrion is taken prisoner by Lady Catelyn Stark and her sister Lysa Arryn, who accuse him of the attempted murder of Bran Stark and the murder of Jon Arryn. Tyrion is ultimately acquitted after a trial by combat in which Bronn champions for him. In retaliation for Tyrion's kidnapping, his father Tywin Lannister invades the Riverlands, effectively triggering war with the Starks and Tullys.