Commandos are normally trained for assault by land, sea or air and most are parachute qualified. Training also includes unarmed combat, infiltration, patrol, reconnaissance, jungle, desert, arctic, and mountain terrains with an emphasis on both teamwork and self reliance. Individuals specialise in various aspects such as explosives and communications and Commando hallmarks are speed, mobility and stealth. Many operations are conducted at night and Commandos are not intended to remain continuously in the line for long periods.
Tactics common to the modern Commando are the product of experience gained over the centuries, but acutely brought to the fore and developed in the 20th century. The term is Portuguese and first came to world attention when adopted by the Boers of South Africa around 1900. The Boers formed "Commandos" among themselves to pursue native African cattle-raiders. Communities and farmsteads were obliged to provide self-equipped mounted men whenever a Commando was mustered—similar to the original Texas Rangers. By the time of the Second Boer War against the United Kingdom, the Boer Commandos engaged the regular British Army quite effectively in hit-and-run and ambush engagements.
The British (who did not have 'Commando' formations in World War I), revived the term in 1940 during World War II with the creation of their Army Commandos, and later the addition of Royal Marines from 1942. The original intention was for them to act as small highly mobile raiding and reconnaissance forces with the capability of combining in the role of shock troops. Commandos were not intended to remain in field operations for more than 36 hours and to carry all they needed. Army Commandos were all volunteers selected from existing soldiers still in Britain. The same volunteer selection process was observed for the formation of No.40 Commando from the Royal Marines. Subsequent Royal Marines Commandos were formed by remustering existing Royal Marines battalions into Commandos. As the war progressed, some selection and training took place in respective theatres of operation. The Army Commandos were disbanded in 1946 though the Royal Marines Commandos continued. Today Britain maintains one brigade of Commandos under the Royal Marines which includes three Royal Marines infantry Commandos, one Army Royal Artillery Commando and one Army Royal Engineers Commando.
During the summer of 1942 the American infantry in Northern Ireland formed the Rangers, under Bill Darby, on the same lines as the British Army Commandos who undertook their training. The first sizeable Ranger action took place in August 1942 at Dieppe (Operation Jubilee) where 50 Rangers were dispersed among the British Commandos. The first full Ranger action took place during the invasion of North West Africa (Operation Torch) in November 1942.
The German Office for Foreign and Counter-Intelligence (OKW Amt Ausland/Abwehr) formed the Brandenburger Commandos (800th Special Purpose Construction Training Battalion) in December 1939. They conducted a mixture of covert and overt operations, but became increasingly involved with line infantry actions and eventually became a Panzer-Grenadier Division, suffering heavy losses in Russia. Otto Skorzeny (most famed for his rescue of Benito Mussolini) conducted many special operations for Adolf Hitler but no Commando organisation was developed from this and technically he remained a Waffen-SS Officer (Sturmbannführer/Major).
Italy's Commandos of World War I, the Arditi, were not reformed in World War II, and their most renown Commandos became the Decima Flottiglia MAS who were responsible for the sinking and damage of considerable Allied tonnage in the Mediterranean. After the division on Italy in 1943, those fighting with Germany retained the original name and those fighting with the Allies retitled as the Mariassalto.