Osmyk first came to prominence after amassing quite a considerable fortune from maritime trade, and probably also a little from buccaneering. When he arrived in Kerack, Osmyk finished off the competition and monopolised the region's cabotage and then declared himself the first king of Kerack. This act of self-anointed coronation actually only formalised the status quo, and hence did not arouse significant quarrels nor provoke protests.

Over the course of various private wars and skirmishes, Osmyk smoothed over border disputes and jurisdictional squabbles with his neighbours, Cidaris and Verden, establishing where Kerack began, where it finished, and who ruled there in the process. During his reign, he derived the majority of his profits from shipbuilding, freight, fishery and piracy.

Osmyk was the father of Belohun who, following the death of his father, became the second king of Kerack. Besides Belohun, Osmyk also had four other sons, but all of them renounced their rights to the crown, and allegedly one of them even did it of his own free will.

In the middle of the town square in Kerack proper, there is a statue of the "founder" of the city King Osmyk, even though a seaside town had existed there long before he arrived from an unknown location.