In the Napoleonic era, artillery became one of the three main combat arms, together with infantry and cavalry. Field guns won many battlefield victories. In 1800 French armies employed about two artillery pieces per 1,000 soldiers. The number increased to as many as five guns per 1,000 by 1812 as the quality of foot soldiers diminished. Under Napoleon batteries usually included eight pieces and the 4-pounder was often employed in advance guards, divisional reserves and horse artillery batteries of the reserve. Frequently, batteries were made up of six cannons and two howitzers. At beginning of the French Revolutionary Wars, all armies attached 3- and 4-pounder cannons directly to the infantry units. They were supposed to be served by trained gunners but in reality they were often worked by infantrymen drafted from the ranks. Each infantry battalion had two 4-pounders attached to it and the guns were frequently called battalion pieces. Partly due to an overall lack of field guns, Napoleon removed the battalion pieces from infantry battalions and combined them into batteries. After his defeat at the Battle of Aspern-Essling in 1809, Napoleon reversed this policy and rearmed his infantry units with battalion pieces.