Supreme Chancellor (usually just Chancellor) is the title of the head of government in the Galactic Republic of the fictional Star Wars universe.
The Chancellor is elected by and from the members of the Galactic Senate and serves as long as he or she can maintain the confidence of the house. The Chancellor can be deposed by a vote of no confidence at any time.
The office was largely powerless in the last years of the Republic, similar in nature to a Speaker of the House. It was still a very prestigious position, however, and the Chancellor had a grand office and was given the title of "Excellency."
Chancellor Finis Valorum was seen in Star Wars Episode I: The Phantom Menace and presided over the dispute between Naboo and the Trade Federation. He was ousted when Queen Amidala, on Senator Palpatine's urging, moved for a vote of no-confidence.
The office became much more powerful during the reign of Chancellor Palpatine, who was able to effectively force the Senate into granting him a series of "emergency" powers. Eventually, Palpatine became a dictator and proclaimed himself Emperor, thus abolishing the office of Chancellor and ending the Republic. This brought about the establishment of the Galactic Empire. The title was not revived by the New Republic
List of Supreme Chancellors