In 1798, he joined general Napoleon Bonaparte's French Campaign in Egypt and Syria, and from 1799 held the position of director of the artillery park of the Army of Egypt, with the rank of Chef de bataillon.

[1] From 1805 onwards, Ruty took part to the campaigns of the Grande Armée during the War of the Third Coalition and War of the Fourth Coalition, serving as artillery park director for the Army Corps of Marshal Michel Ney, then Marshal Joachim Murat.

[2] He contributed significantly to the successful sieges of Ciudad Rodrigo and Almeida, before taking command of Marshal Jean-de-Dieu Soult's artillery in the armies of the South and of Andalusia.

In 1813, Ruty was recalled to France, and promoted to general of division, before being named commander of Marshal Nicolas Oudinot's Corps artillery during the Saxon campaign of the War of the Sixth Coalition.

After Napoleon's abdication in 1814, Ruty served the Bourbon Restoration, but during the Hundred Days he joined the Emperor, who named him commander of the artillery of the Army of the North, with Ruty playing a significant role at the battle of Waterloo.