Carl Palgrem was the revolutionary leader of the Sirius Revolutionary Congress, who instigated the rebellion against the Earth Unity Government that culminated in the Earth-Sirius War and the destruction of Earth by the Black Fleet.
By the late 27th century, the political dominance of the Humanity Congress began to wane. Dissatisfied with unfair congressional represntation, a number of colonies rebelled against the Earth Unity Government, led by the charismatic revolutionary Carl Palgrem. The dominant force in opposition of the EUG was the Sirius colony, led by the charismatic Carl Palgrem. Palgrem's rebels quickly adopted the name Sirius Revolutionary Congress, and declare themselves independent from the EUG, thus instigating the Earth-Sirius War.
In 2689, the Earth Unity Government's Department of Public Safety launched an invasion of the Sirius starzone, occupying the colony on Sirius VI, Rondolina. The occupation army was extremely undisciplined, resulting in a brutal occupation, eventually culminating in a massacre of thousands of civilians in Rondolina's capital city, Laglane.
By 2689, the Sirius Revolutionary Congress succeeds in liberating Rondolina after winning a series of astonishing victories against the undisciplined forces of the EUG's Department of Public Safety. After driving the EUG navy from Sirius, Carl Palgrem's Black Fleet procedes to Earth itself, initiating a two-month-long blockade of the planet. Weakened and starving from the blockade, the Earth Unity Government was unable to defend itself when the Black Fleet descened on the planet, bombarding the Earth from orbit with nuclear weapons. The planet's crust was destroyed and the Earth is rendered uninhabitable: the entire population is killed, effectively annihilating the Earth Unity Government.
Shortly after the end of the Earth-Sirius War, Carl Palgrem died (of unknown causes) and his revoluationary movement fragmented into dozens of independent city-states, bringing to the scattered human settlements an age of chaos that would endure for 100 years.