Originally Posted by NCC-73515
When was the Klingon neutral zone established?
The Klingon Neutral Zone was established in the aftermath of the events depicted in the TOS episode, "Errand of Mercy;" I believe it was enforced by the Organians. In fact, if I'm not mistaken, it was referred to on occasion as the "Organian Neutral Zone." I guess that puts it in about 2266 - '67, according to the Prime Timeline.
Just so ya' know.