First Lord of the Treasury
head of the commission exercising the ancient office of Lord High Treasurer in the United Kingdom
The First Lord of the Treasury is the head of the commission exercising the ancient office of Lord High Treasurer in the United Kingdom, and is by convention also the prime minister. This office is not equivalent to the usual position of the "treasurer" in other governments; the closer equivalent of a treasurer in the United Kingdom is chancellor of the exchequer, who is the second lord of the Treasury.