Artillery has been a primary weapon of war since before the Napoleonic Era. Several countries have developed and built artillery systems, while artillery itself has been continually improved and redesigned to meet the evolving needs of the battlefield. This has led to a plethora of different types and designs which have played a role in the history of warfare and continue to be a significant factor in modern combat. For other categorized lists, see list of artillery by country and list of artillery by type.