Yet to be crowned: an uncrowned queen. (adjective)
Having the power or influence of a monarch or other prominent figure but not the title: the uncrowned king of the espionage world. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "uncrowned" in a sentence
"On Sunday, he went to a Friends meeting, where he listened to Rufus Jones, whom he called the uncrowned Quaker pope."
"Their leader, Heydebrand, is known as the uncrowned king of Prussia."
"Vollmar, for example, who in his own land possesses so great an influence that he has been called the uncrowned king of Bavaria, cannot consent to play second fiddle in the German national organization."