Because of its common language, values and internal relations, each regiment tends to form a strong cohesion among its members.
Each has its own history, traditions and culture.
Young recruits are raised to become members and old veterans are cared for after demobilization.
Experience is passed from generation to generation.
The big advantage of regiments is that they create an "esprit de corps",
a strong morale that keeps its soldiers fighting for their unit long after they have stopped caring about the objectives of the war.
The great disadvantage is that it is almost impossible to split, merge or otherwise reorganize regimental units.
On the battlefield, most fight not only as single organizational, but also single tactical units.
Regiments that are forced to work together often develop rivalry, which can seriously hamper co-operation but on the other hand prevents unified revolts by army troops.
Regiments work best when they are employed far from home.
Regiments arose from the mercenary companies of the Late Middle Age.
In the 15th century CE, king Charles VIII of France pioneered the development, by stopping to disband his mercenaries after a campaign, transforming them into a standing army.
This army, like those of later copycats, was relatively small.
It was not until the 17th century CE, when states managed to strengthen their tax base, that large standing armies could be supported.
Nonetheless regimental armies were significantly larger than their Medieval counterparts.
Traditional regiments numbered around 1,000 men, including some 10 companies.
During the 18th century CE the regimental system became increasingly popular and was adopted all over Europe,
until it was shattered by French revolutionary armies at the end of the century.
Some countries, who were the least affected by the French wars, retained the system until this day.
The most prominent examples are Sweden, Great Britain, the Commonwealth countries and the USA.
Other countries switched to the 'continental system' of numbered, not named, units partitioned by administrative motives.
War Matrix - Regiments
Age of Discovery 1480 CE - 1620 CE, Armies and troops