The terror was fully part of the revolution, and was notably when the vote for France to proclame itself a Republic happened. Support for and against the king came and went throughout the revolution. The vote for abolition of monarchy in 92 (so, 3 years after it began!) and then for death penalty of the king in 93 was heavily influenced by the fear of retribution for whom may vote against. France would likely still be a monarchy if not for the terror.

FWIW, France became an empire, then was restored as a monarchy, then back an empire and monarchy before it became a republic durably.

Revolution was not a series of peasants and commoner ridding themselves of their despots, it was much more dirtier, political and complex than that, which doesn't prevent to still be behind the ideals that drove the events and find it beautiful.