Catherine can be described a such because she had no constitution for her country. She ruled by her own decision not by a written code. Her laws had to be upheld. She herself quoted that, "The Sovereign is Absolute."
hope that helped;P
The "Big Three" countries were the United States, Great Britain and Russia. They were called this because they were by far the most important allied players during the war, with Russia and Britain taking on most of the casualties.
