Earth-Minbari war

The Earth–Minbari War is a fictional war that formed a major part of the back story of the science fiction television series Babylon 5. The war began in 2245 when an EarthForce (Earth's military force) expeditionary fleet damaged and destroyed vessels of the Minbari Federation fleet, killing Dukhat (leader of the Minbari Grey Council). The Earth fleet's commander misinterpreted the Minbari warrior caste's tradition of approaching a ship with gun ports open as a hostile action and fired on the Minbari vessels. In retaliation for this incident, the Minbari went on a genocidal crusade against Earth and all humans.

The war lasted for two years with Earth Alliance being almost totally outmatched by the Minbari and ended with the unexpected Minbari surrender at the Battle of the Line. The Minbari surrender occurred when they believed that the souls of dead Minbari were being reincarnated in humans and that they shared DNA with the human race. This revelation became part of the story arc of the show and the events of the war itself are depicted in the Babylon 5: In the Beginning TV Movie.

The seeds of the war were planted when Earth Alliance, flush from their victory in the Dilgar War, was expanding its influence and decided to explore Minbari space. Despite the warnings of Centauri Ambassador Londo Mollari that the Minbari are an ancient, powerful species and dangerous if provoked, a flotilla of armed vessels was dispatched and led by Captain Michael Jankowski, who was appointed over the objections of capable officers like John Sheridan who considered the captain unsuited to delicate operations like this.

As feared, the war was provoked by Captain Jankowski aboard the warship EAS Prometheus. During the expedition, the Prometheus and her escorts encountered three Minbari cruisers, one of which was carrying the Grey Council, the highest echelon of Minbari society. The Grey Council was en route to investigate reports of sightings of their ancient enemy, the Shadows. Although Jankowski had been given strict orders to not do anything which might be perceived as hostile, Jankowski disobeyed the orders and refused to jump to hyperspace when the Minbari spotted his fleet. He thought that by waiting to the last possible moment to jump, he could gain valuable sensor information about the Minbari cruisers, and this would lead to a promotion and medals from Earthforce Command.

...
Wikipedia