In 2152, Duras, son of Toral was demoted to second weapons officer and sent to serve at Ty'Gokor's defense perimeter after his failure to apprehend the Raatooran rebels at the hands of Captain Jonathan Archer of Enterprise NX-01. (ENT: "Judgment")
By 2373, Chancellor Gowron had moved Klingon military headquarters from Qo'noS to Ty'Gokor. The planetoid was protected by a powerful defensive shield and a tachyon detection grid, as well as several orbital facilities. At least thirty Klingon warships were stationed near it at all times.
A small team led by Captain Benjamin Sisko was able to infiltrate Ty'Gokor with the help of Gul Dukat's stolen Bird-of-Prey. There, they exposed General Martok as a Changeling. (DS9: "Apocalypse Rising")
Background information Edit
According to the script for "Apocalypse Rising", Ty'Gokor's name was pronounced as "TIE-go-kor".  Ty'Gokor itself was described in the script as "a fortified asteroid covered with defense installations, ship docks and weapons platforms. Several other Klingon ships keep watch over the planetoid."
According to Star Trek: Star Charts (p. 63) and Stellar Cartography: The Starfleet Reference Library ("Stellar Cartography", pp. 31; "Federation Historical Highlights, 2161-2385”), there was a star system named Ty'Gokor, in which this planetoid might possibly have been located, in the Beta Quadrant. The system's primary was a K-class star.
Ty'Gokor is also mentioned in The Left Hand of Destiny, Book Two.
The Klingon trading station in Star Trek Armada 2 appears much like the stations in orbit of Ty'Gokor.