Mamluk or mamaluk were non-Arab, ethnically diverse enslaved mercenaries, slave-soldiers, and freed slaves who were assigned high-ranking military and administrative duties in the Muslim world. They were purchased as military slaves, converted to Islam, and trained in martial and courtly skills. Upon completion of their training they were freed, but remained part of the ruling military caste, forming elite regiments and, in some periods and regions, rising to sovereign power.