Swiss mercenaries had been extremely famous in pre-modern Europe, yet in the mid-19^th century, the young Swiss Confederation illegalised foreign military service. Nevertheless, a large number of Swiss men would serve in foreign mercenary armies during the 19^th and 20^th centuries. This article concentrates on this group’s social structure and their motivations. The overwhelming majority originated from the lowest strata of society. They had week family ties, were poorly educated and lacked any career perspectives. Most of them when entering foreign military service were in only temporary employment as unskilled workers or even unemployed. Foreign military service, especially in the French Foreign Legion, thus was to many of them a last resort, rather than the romantic adventure it was portrayed as in contemporary movies and novels. However, soldiers’ and ex-soldiers’ perceptions of this service varied considerably. Whilst some of them simply compared it to slavery, others emphasized career opportunities, either in the military hierarchy or in their post-mercenary lives through skills acquired during their military service.