(covers information from several alternate timelines)
This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
In 2016, a Vulcan starship crossed into Klingon space near H'atoria and was immediately destroyed by the Klingons. In the aftermath, Vulcans established a policy of firing first when encountering Klingons, earning their respect and eventually leading to the establishment of formal relations. (DIS: "The Vulcan Hello", "Magic to Make the Sanest Man Go Mad")
In 2256, Hatoria's location was labeled on the star chart "Alpha/Beta Quadrant Overview" in the ready room aboard the USS Discovery. It was located in the territory of the Klingon Empire. (TNG: "All Good Things..."; DIS: "Magic to Make the Sanest Man Go Mad", "The War Without, The War Within")