Gustavus Adolphus of Sweden emphasized the use of light cannon and mobility in his army, and created new formations and tactics that revolutionized artillery. He discontinued using all 12 pounder—or heavier—cannon as field artillery, preferring, instead, to use cannon that could be manned by only a few men. One gun, called the "leatheren," could be serviced by only two persons, but was abandoned, replaced by 4 pounder and 9 pounder demi-culverins. These could be operated by three men, and pulled by only two horses. Also, Adolphus's army was the first to use a special cartridge that contained both powder and shot, which sped up loading, and therefore increased the rate of fire. Additionally, he pioneered the use of canister shot against infantry, which was essentially a can, filled with musket balls. At the time, for each thousand infantrymen, there was one cannon on the battlefield; Gustavus Adolphus increased the number of cannon in his army so dramatically, that there were six cannon for each one thousand infantry. Each regiment was assigned two pieces, though he often decided to arrange his artillery into batteries, instead. These were to decimate the enemy's infantry, while his cavalry outflanked their heavy guns. At the Battle of Breitenfeld, in 1631, Adolphus proved the effectiveness of the changes made to his army, in particular his artillery, by defeating Johann Tserclaes, Count of Tilly. Although severely outnumbered, the Swedes were able to fire between three and five times as many volleys of artillery without losing ground, due to their infantry's linear formations. Battered by cannon fire, and low on morale, Tilly's men broke rank, and fled.