The Demand for Unity was a decree made by the Orion Emperor Boyor Ignatin the Righteous less than a year after he seized power on March 21st, 1003 CE (reference stardate -10/0303.21).
After he was crowned Emperor, Boyor issued the Demand for Unity to all seceded and rebellious Orion Colonies. When that didn't work, he sent the Orion Space Navy to bring these worlds back under the control of the Botchok Planetary Congress, triggering the Fringe Wars. (FASA RPG module: The Orions: Book of Common Knowledge)