By the time of the Napoleonic Wars battlefield artillery had become common place, its mobility and firepower had increased and battles could be won or lost by effective use of artillery. How much a commander relied on artillery varied greatly. Wellington never had much during the Peninsula War and frequently had to rely on taking fortresses by storm rather than reducing them with a siege train, as in the siege of Badajoz (1812). Napoleon with his background as an artillery officer made much more effective use of it and often massed his guns as at Waterloo in a grand battery. In contrast, the Austrian Army of the time often spread its artillery throughout its forces to offer support where it was needed, but this just diluted its effectiveness. France, Spain, and Bavaria adopted a standard system of 4pdr, 8pdr and 12pdr guns - what was known as the Gribeauval system named after the French Inspector General of artillery who had introduced it in 1776. It should be noted that weights were not standard in the 18th Century so a French 8pdr actually was equal to 8.8 British pounds.
Napoleonic artillery consisted of horse artillery, which was generally light and mobile field artillery and siege guns, which were generally too heavy and slow to be much use on the battlefield. The main weapons were cannons (firing canister or round shot) and howitzers (which fired on a high trajectory, normally using exploding shells). The British also introducedCongreve Rockets by the end of this period. The firepower of artillery in this period is often over estimated and at longer ranges could cause few casualties but like artillery throughout history had a considerable psychological impact on those under fire. Round shot made up around 70% of all ammunition fired and if used correctly could shatter a wagon or destroy a horse bouncing through troops in column formation but doing little to those in line unless fired at right angles. A French 8pdr gun (or British 9pdr) would have an effective range of about 800 yds with roundshot, which could then bounce or second graze for a considerable distance after impact, or 500 yds with canister (a cartridge filled with musket balls having a shotgun-like effect at close range). Canister was not always effective and the British normally did not use it at ranges beyond 350 yds but it could be lethal and tests indicated that a 6 pdr could deliver 55 hits at 200yds but this dropped to only 6 hits at 600 yds. Rate of fire was thought to be about 2 roundshot or 3 canister per minute in battlefield conditions. Field artillery could keep up with the main army in good weather covering 10 -15 miles a day although a British 6 pdr gun carriage and limber would take up 60ft of road while in transit!