These characters can be dropped into Imperial history at any convenient point.
Emperor Dybor "the Tyrant" (negative sanguine) —
His brutality, ethnic pograms, and purges of imperial bureaucracies and planetary governments sparked a bloody series of insurrections, followed by military occupations of dissident planets, ending in a dynastic civil war and his death.
Empress Lissar "the Great" (positive sanguine) —
This dynamic ruler renewed Imperial efforts at terraforming, started many other public works projects, built up the Imperial merchant marine, brought piracy by surviving Koliots to a halt both within the Empire and through much neighboring space, and fostered friendly relations with other governments.
Emperor Garrol "the Priest-King" (negative melancholic) —
His doctrinaire approach to Ideolatry led him to persecute other religions and psychics, while his over-developed sense of hierarchy and decorum led to unpopular sumptuary laws and the elevation of many rules of etiquette regarding titles and stations into laws. He also ran campaigns for moral purity regarding marriage codes and recreations, especially regarding psychoactive substances and the media content.
Emperor Kelem II, "the Reformer" (positive melancholic) —
This enlightened ruler released large numbers of political prisoners, overhauled police systems Empire-wide, repealed the slavery laws, took steps to ensure Old Settlers equal opportunities for advancement, and declared toleration for psychics.
Empress Neriket III, "the Ice Queen" (negative phlegmatic) —
Her cynical methods included the establishment of a secret police, wide-spread control of the media and use of propaganda both direct and subtle, and control of the Senate and planetary governments by blackmail and the deliberate fostering of general corruption.
Emperor Vaspan "the Wise" (positive phlegmatic) —
This political architect instituted many economic reforms, boosted the educational systems and technological industries, exercised firm but humane crime control, and reformed the GATs (Governance Aptitude Tests).
Empress Mellashi, "Sugar" (negative choleric) —
This decadent ruler regarded her office as a prize to be enjoyed. She was indifferent to matters of state, using her high intelligence to play factions off against one another, maintaining a political stalemate in which economic and societal problems slowly worsened. Meanwhile, she and her court provided every kind of bad role model.
Empress Ilanda, "the Merry Empress" (positive choleric) —
Charismatic and ever-youthful, she set a widely-followed example for public charity, patronage of the arts, and general tolerance of out-groups. She also revitalized the Imperial terraforming program.