At the opening of the National Convention the Montagnard group comprised men of very diverse shades of opinion, and such cohesion as it subsequently acquired was due rather to the opposition of its leaders to the Girondist leaders than to any fundamental hostility between the two groups. The chief point of distinction was that the Girondists comprised mainly theorists and thinkers, whereas the Mountain consisted almost entirely of uncompromising men of action.
During their struggle with the Girondists, the Montagnards gained the upper hand in the Jacobin Club, and for a time "Jacobin" and "Montagnard" were synonymous terms. The Mountain was successively under the sway of such men as Marat, Danton, and Robespierre, and the group finally disappeared after Robespierre’s death (28 July 1794) and the successes of the French arms.