Esterad (and his father before him), lived through a very difficult period for Kovir and the House of Thyssen in particular. The first of several bloody power struggles occurred with the Secession of Poviss, when Rhyd declared himself King of Poviss and thus autonomous. He gained independence as did the East March (which later split into several duchies and kingdoms, only to finally unite as the "Hengfors League"). But the worst was yet to come - there was a revolt and Baldwin lost control of his crown to Idi, and for the first time in the history of the house, the Thyssens were forced to flee. During his escape, King Baldwin suddenly died, probably due to a brain aneurysm. Because of this, Esterad spent most of his youth in exile in Talgar.
But he did not bide his time unproductively. Esterad considered various plans, gathered his strength, and gained adherents, forging secret pacts and alliances. Finally, he struck back, and decisively. One night, known ever since as the Night of Knives and Torches, Idi, Rhyd and their entire families were killed and the House of Thyssen was restored.
Although Kovir was officially neutral, Esterad helped the Northern forces by granting royal pardon to the prisoners in his kingdom, many of which later formed the Free Company led by "Adieu" Pangratt.
He was killed on the stairs of his own palace by assassins, choosing to stay and protect Zuleyka instead of fleeing.
- In The Witcher 2: Assassins of Kings, Letho of Gulet revealed that Esterad was supposed to be the first target of the Kingslayers, but thanks to the unintentional intervention of Sheala de Tancarville this never happened and their first target ended up being King Demavend III, the ruler of Aedirn.
- His name is mistakenly mentioned as "Esmerad Tyssen" in the second game.
- In The Witcher 3: Wild Hunt, he's featured on a gwent card, Esterad Thyssen.