The French Foreign Legion is known as an elite military unit whose training focuses not only on traditional military skills but also on its strong esprit de corps. As its men come from different countries with different cultures, this is a widely accepted solution to strengthen them enough to work as a team. Consequently, training is often described as not only physically challenging, but also extremely psychologically stressful.

The Legion was primarily used to protect and expand the French colonial empire during the 19th century, but it also fought in all French wars including the Franco-Prussian War and both World Wars.

Although considered an anachronism by some, the Foreign Legion has remained an important part of the French Army. It has survived three republics, one empire, two World Wars, the rise and fall of mass conscript armies, the dismantling of the French colonial empire and, finally, the French loss of the legion's birthplace, Algeria.

Source: Wikipedia