The original British Ordnance ML 3-inch Mortar of World War 2 proved its worth and then some throughout the global conflict. The weapon was fielded in great numbers with British Army and Commonwealth Forces and found a home in a few other global inventories. The type served well into the 1960s by which time thought was given to providing indirect fire elements a new, more modern weapon system. A joint Canadian-United Kingdom development effort produced the excellent L16 81mm series, to which the type was accepted into service with the British Army in 1965 as the L16A1. It has since been improved with the follow up L16A2 with a plethora of nations following the UK lead.
The L16 serves as an "indirect fire" weapon meaning that line-of-sight of the target is not a requirement for the operating crew. The mortar instead attacks a target area as opposed to a direct target and supplies accompanying infantry with fire support during an offensive or defensive action. Systems such as the L16 are designed to be somewhat portable but they can also be fired from vehicles designed to mount the weapon (usually a tracked carrier). In this fashion, the L16 becomes a highly mobile fire support system capable of going wherever the modern mechanized force can go. Additionally, its portability means that the L16 can be transported at speed and setup within a short window of time, ready to attack enemy emplacements as directed. The L16 - and its global derivatives - have proven highly effective in its roles to date.
Design for the new infantry-level mortar began in 1956 under the leadership of the Royal Armament Research and Development Establishment and Fort Halstead. Fort Halstead was charged with the development of the barrel and bipod assemblies. After evaluations and formal acceptance, a serial production effort was initiated with Royal Ordnance heading up the move. Production began promptly and, in 1965 and into 1966, the L16 mortar series formally replaced the wartime Ordnance ML 3-inch Mortar system within the inventory of the British Army. The weapon went on to see extensive combat service in Borneo, South Arabia, Oman, the Falklands War, the Balkans War, the Gulf War of 1991, the invasion of Afghanistan and - most recently - in the invasion of Iraq in support of coalition forces. All told, the L16 has proven a reliable and robust gunnery platform in all environments.