A secretary, secretary of state, or minister of a king or other high nobleman.
The king's chancellor in England during the Middle Ages was given a variety of duties, including drawing up writs that permitted the initiation of a lawsuit in one of the common-law courts and deciding disputes in a way that gave birth to the system of law called EQUITY. His governmental department was called the Chancery.
The Chancellor of the Exchequer in England is like the secretary of the U.S. treasury, but in former times he also presided over a court called the Court of Exchequer, which at first heard disputes over money owed to the king but eventually heard a wide variety of cases involving money. This jurisdiction was founded on the theory that a creditor who could not collect a debt would later be less able to pay whatever he owed to the king.
Chancellor has also been used as the title for a judge who sits in a court of equity, for the president of a university, or for the public official in charge of higher education in some states.