This first encounter with the Hegemony was hostile, as the Gorn were claiming Cestus III – a world which was then occupied by a Federation settlement – as their own. Despite this, the two powers had resolved the conflict over Cestus III by the 2370s, when a Human settlement thrived there. (TOS: "Arena"; DS9: "Family Business")
Prior to actual contact there was little known of the Gorn by Earth. Among the minor bits of knowledge that did exist was that, according to Orion privateer Harrad-Sar in 2154, a planet in the Gorn Hegemony brewed "the finest meridor in the five systems". (ENT: "Bound")
The name of this government was revealed in "Bound", although there was apparently no official UFP contact with the Gorn until Kirk's era. Federation-Gorn relations were described, in the Star Trek Encyclopedia, as "cordial" during the 2370s. The name "Gorn Hegemony" had been used in non-canon books and games for years before this episode was written, however.
In the novel Articles of the Federation, one of the characters says that the crew of the USS Enterprise convinced the Gorn to join the Federation Alliance and fight against the Dominion in the war. This is from the graphic novel "The Gorn Crisis" by Kevin J. Anderson and illustrated by Igor Kordey. But in the game manual for Star Trek: Bridge Commander, it is stated that the Gorn sided with the Dominion. The Star Trek: Destiny novel Mere Mortals by David Mack establishes that the Gorn Hegemony had an embassy to the Federation located in Berlin and its head of government was the Gorn Imperator. In A Singular Destiny, the Gorn allied themselves with the Romulan Star Empire, the Tholians, and others antagonistic towards the Federation and Klingons.
In Star Trek Online, by the early 25th century, the Klingons had conquered the Hegemony and absorbed the Gorn into the Empire. The story line of the game also states that a monarch, King Slathis, was the head of the government.
The twenty-fourth issue of the Star Trek: Ongoing comic book series features a group of Gorn who had rebelled and settled on the planet Parthenon 559 wanting to live in peace. But because of the previous encounter as mentioned above, the Humans who came to mine the planet reacted with hostility. Kirk resolved everything and forced the Humans off of the planet after learning more about the Gorn in the process. The issue also potentially provides another origin story for the Gorn Hegemony.