When Crydee became aware of the threat of to the Kingdom posed by the Tsurani, Lyam was left in command as his father left to bear the warning to Krondor and then Rodric in Rillanon. During his command of the Crydee he followed the advice of Swordmaster Fannon instead of that of his brother. At the start of the third year of the war he left Crydee to becomes his fathers aide-de-camp in Yabon. He was succeeded as commander by Fannon instead of his brother who was by this time the same age that Lyam had been when he gained command.
Near the end of the Riftwar his father is mortally wounded and as he lays dieing Lyam has to put thought to the message of a possible treaty brought by Kasumi and Laurie from the Emperor. At the time of his fathers death the heir to the throne Prince Erland of Krondor is dead so he becomes heir to the throne. On his deathbed Borric recognises Martin Longbow as his eldest son, which shocks Lyam. SHortly before his death from wounds in battle Rodric names Lyam as his heir as eldest male ConDoin. This disturbs Lyam as Martin should have first claim. Lyam agrees to peace with the Tsurani and during the peace treaty signing he takes part in the battle after the betrayal of Macros the Black.
Lyam becomes King of the Isles despite telling Martin that he should be heir as Martin renounces his claim and those of his future progeny. Pug and Kulgan believe that he would make a good King as people would follow him to death. After his coronation he sets out on a tour of the eastern realms with his two brothers.