CROWN

The word refers specifically to the British Monarch, where she is the head of state of Commonwealth countries. Prosecutions and civil cases taken (or defended) by the government are taken in the name of the Crown as head of state. That is why public prosecutors are referred to, in Canada, as "Crown" prosecutors and criminal cases take the form of "The Crown vs. John Doe" or "Regina vs. John Doe", Regina being Latin for "The Queen."