Question

what drastic changes were brought about by the national assembly in 1798

Answer 1

The National Assembly of 1789 (not 1798) was a revolutionary assembly consisting of members of the Third Estate. The most revolutionary change instituted by the Assembly was the Declaration of the Right of Man and the Citizen. This declaration proclaimed the freedom of every citizen of France and declared every citizen equal before the law. It, therefore, abolished feudalism.

The Assembly also proclaimed France to be a constitutional monarchy and, thereby, abolished the arbitrary exercise of authority by the king.