The French Convention decreed a levée en masse on 23 August 1793 to resist the anti-French coalition:
From this moment until such time as its enemies shall have been driven from the soil of the Republic, all Frenchmen are in permanent requisition for the services of the armies. The young men shall fight; the married men shall forge arms and transport provisions; the women shall make tents and clothes and shall serve in the hospitals; the children shall turn old lint into linen; the old men shall betake themselves to the public squares in order to arouse the courage of the warriors and preach hatred of kings and the unity of the Republic.
This state of total war marks a historic turning point. Never before in history had all men, women, children, and elderly in an entire country been requisitioned for war. This caught the coalition completely off guard. Armies until then were the affair of professionals (and mercenaries). France overwhelmed the rest of Europe to the point where they had to expand their troop counts far beyond their ability to pay professional soldiers
At least a few historians (e.g. J.M. Roberts) emphasize the introduction of total war by France as one of the major breaks with the past that opened the modern era.