Belohun was the second king of Kerack, son of Osmyk, and father of 6 sons and 8 daughters, though only 4 of the sons had any legal claim to the throne. By 1245, he'd ruled for over 20 years and it was believed he was in good enough form that he'd rule for another 20.
Belohun came into power after at least 4 other brothers all renounced the right to Kerack's throne, one of whom did so willingly, and thus it fell onto Belohun as the new successor. Following in his father's steps, he derived profits from the small kingdom through their maritime trade, including piracy. However, this was a clear double-standard: while piracy was fine, he hated those who embezzled funds from the royal purse. The sorceress Lytta Neyd, who visited in 1245, used this to prompt Belohun to throw Geralt into jail under false embezzlement charges for 4 days as part of her plan to get the witcher to do her bidding.
By 1245, Belohun had gone through at least 4 wives, each one having mysteriously died when he got bored and found a new one to marry, and thus had 4 legitimate sons but all with a different mother. Despite this, he'd banished the eldest, the second was a deranged drunk kept out of sight, and the last two, Egmund and Xander, didn't seem fit to take over, and thus the king decided to take on another wife to try for another son and heir, not hiding this fact from his last two legitimate sons. So, in the summer of 1245, he became engaged to Ildiko Breckl and planned to wed soon after.
Outraged by this, Egmund and Xander organized a coup d'état, ordering a poisoner to put some contact poison on Belohun's poker.
The plan however failed, since the poisoner betrayed the two princes and told the truth to Belohun, who then imprisoned Egmund and Xander.
Later, while Belohun was wearing his ceremony dress, a magic necklace gifted to him from Ildiko Breckl, wrapped around his throat and suffocated him. The medic, who arrived soon after, wrongly ascertained that Belohun died from an epileptic fit.