During the Peake Uprising, Tywald fought on the side of King Maekar I Targaryen against the rebellious House Peake. He was mortally wounded by a spear during the Storming of Starpike. Prince Aegon knighted the squire as he died in the arms of his twin. Tywald supposedly asked, with his last breath, for Tion to "take care of Lady Ellyn". It was this that caused Gerold Lannister to agree to betrothing Tion to Ellyn.