Rise to power
Gowron first appeared in the TNG episode "Reunion" and was one of two candidates vying for the seat of Chancellor, the head of the Klingon High Council. Though an ambitious man, he accepted the former Chancellor K'mpec's decision to name Captain Jean-Luc Picard of Starfleet his Arbiter of Succession who would deem whether or not Gowron was worthy of leading the Klingon Empire. Gowron's opponent for succession was Duras, son of Ja'Rod, who had previously discredited Worf's family, the House of Mogh, and was infamous for his duplicity. When Worf killed Duras as was his right of vengeance, Gowron ascended to the Klingon throne unchallenged. Though an inexperienced leader, he earned his chancellorship by leading the Klingon Defence Force in battle against the House of Duras during the Klingon Civil War which took place in the two-part episode "Redemption".
Leader of an empire
During his term as Chancellor, Gowron organised the Klingon Empire's invasion of Cardassia, believing that the Cardassian Union was under the control of the Dominion. Little did he know that changelings had infiltrated the Empire and were misleading him into waging war not only against the Cardassians, but also the Empire's greatest ally, the United Federation of Planets. The Klingon-Federation treaty would be reinstated when the Dominion made their entry into the Alpha Quadrant, though Gowron was initially hesitant about the idea.
In the closing days of the Dominion War, Gowron assumed direct military command of the Klingon Defence Forces. His motives for doing so, however, where entirely personal. Gowron had come to regard General Martok as a political rival, though Martok held no interest in politics. The Chancellor organised a number of raids against the Dominion that Martok commanded, but these assaults were never meant to be successful and Martok and his troops found themselves outnumbered and outmaneuvered. Realising that Gowron's plans to humiliate Martok were endangering the Empire's war effort by squandering its resources and soldiers, Worf and Captain Sisko agreed that something had to be done to stop Gowron before he lead the Klingon Empire to ruin.
In the DS9 episode "Tacking Into The Wind", Worf challenged Gowron's leadership in front of his council of generals. The Chancellor answered Worf's challenge and the two Klingons fought with bat'leth swords. While Gowron's combat skills were not as great as Worf's, he was driven by anger and a desperate need to hold on to power. He managed to break Worf's bat'leth in half, but as he moved in for the kill, Worf brought up one of the two pieces of bat'leth and stabbed Gowron in the gut, killing him.
With Gowron dead, Worf had won the right to lead the Klingon Empire. He declined chancellorship, however, believing that General Martok was destined to become the next Chancellor and bestowed power on to him.