Fornia had been a peaceful planet for centuries. Surface facilities included research laboratories, observatories, dams and power generators. Explosives and weapons were kept in a central location in the capital city.
In 2266, the starship USS Enterprise paid a diplomatic visit to Fornia. As James T. Kirk and Spock met with government officials, Fornia was bombarded by an orbital beam weapon of immense power. It was a prelude to the arrival of an invasion force led by Klingon Commander Tharrk, who proclaimed himself military governor of Fornia. He demanded an immediate surrender or his orbiting weapon would further damage planetary facilities.
Kirk and Spock hastily escaped from the government building, ordered the Enterprise to leave orbit, and devised a strategy to take out the beam weapon aboard Tharrk's battle cruiser. Kirk promised that the Federation would defend Fornia against future Klingon attacks. (TOS comic: "Smoke and Mirrors")