Martok was a Klingon warrior who rose to the rank of general in the Klingon Defense Forces and later became Chancellor of the Klingon High Council. His brilliant leadership during the Dominion War made him very popular both among other warriors and among the civilian population. As the leader of the House of Martok, he became a good friend of Worf while the two were stationed together on Deep Space 9.
Martok was born in the lowlands of the Ketha Province on Qo'noS to a common family. Fifteen generations of Martok's family had served the Empire as warriors, but Martok's father had hopes that Martok could become an officer. It took some doing, but Martok was able to take the entrance exam and passed. After getting the "stamp of Kor" for lacking noble blood, Martok was reduced to a civilian laborer. During a battle with the Romulans while serving on ShiVang's flagship, Martok's ship was boarded. Martok acquitted himself so well in the fighting that he earned a battlefield commission. He worked his way up and rose in ranks until finally achieving the rank of general.
Some time between 2368 and 2372, Martok was replaced by a Changeling. His whereabouts were unknown until he was rescued from Internment Camp 371 in 2373. Late that year, Martok was given his first field assignment following his imprisonment – command of the IKS Rotarran, and later, command over the Ninth Fleet.
After Chancellor Gowron had taken command over the Klingon forces, Worf challenged him in a battle to the death, for dishonoring the Empire and the Klingon soldiers. When Worf killed Gowron, Worf gave the title of Chancellor to Martok.