Yos Kolina was a Mon Calamari male who reigned as the King of Mon Cala in the final years of the Galactic Republic. His time as king was brought to an abrupt end when he was assassinated by the Separatist operative Riff Tamson. His son, Lee-Char, would eventually avenge this act by killing Tamson.
During the last years of the Republic, Yos Kolina held the position of the 82nd King of Mon Cala. During this time, he fathered a son, the Prince known as Lee-Char. Furthermore, Kolina successfully maintained a peaceful relationship with Nossor Ri, the Quarren chieftain, which preserved the peace between their respective peoples.
However, in 20 BBY, the Separatists, at the request of the Quarren, dispatched Commander Riff Tamson to Mon Cala as an ambassador and observer. Kolina then requested assistance from the Republic and the Jedi Order to prevent his world from collapsing into civil conflict. Subsequently, Tamson assassinated Kolina, having been promised control of the planet by Count Dooku. During a major battle, Lee-Char later killed Tamson, thus avenging his father's murder, and a coronation was later held for him, where he was crowned king with the support of Nossor Ri.