By the 1940s, the expression had spread beyond military leaders. It also included civilian officials.
A newspaper in the American city of Philadelphia used the term in 1949. It called the most important police officials top brass.
Other expressions that mean boss or employer have nothing to do with brass or hats.
One of these is 'big cheese'. A cheese is a solid food made from milk.
The expression probably started in America in the late 19th century.
Some experts believe it comes from a word in the Persian or Urdu languages.
Cheese, the meaning is a thing. So the meaning of ' big cheese' may be a big thing.
Other experts say the word cheese and its expression was really in incorrect way of saying chief.
The word chief means leader. So the expression may mean big leader.
