To what extent did the French Revolution adhere to the principles of liberty, equality and fraternity?
Not sure if this will answer your question, but these are my thoughts. The french started their little revolution a little while after the american revolution. basically, they saw what we were doing and said "hey! that sounds like a good idea! who needs a king?". Keep in mind that the french hadn't had the best experience in government or in any ruling of their country - it was pretty unstable. America was willing to help in Canada, but the French became extremely blood thirsty so America stepped out of it. They said it wasn't just a Revolution anymore, it was more like revenge (not that they had a particular reason or person pinpointed). for the literal definition of the word "fraternity", yes, it was, quite. However, they people of France sought equality and betterment of their lives only in the beginning. Not so much in the end. As for liberty, yes because the King and Queen at that time didn't really know how to properly rule a country... of course they were just kids, but that's a different matter.
chnm.gmu.edu/revolution/
The French Revolution (1789-1799) was a period of major political and social change in the political history of France and Europe as a whole, during which the French governmental structure, previously an absolute monarchy with feudal privileges for the aristocracy and Catholic clergy, underwent radical change to forms based on Enlightenment ideals of democracy, citizenship, and inalienable rights. These changes were accompanied by violent turmoil, including mass executions and repression during the Reign of Terror, and warfare involving every other major European power.