Strateia (Greek: στρατεία) is a term used in the Byzantine Empire, which according to the Oxford Dictionary of Byzantium "signified enrollment into state (civil or military) or ecclesiastical service and the attendant obligations".
The most common usage of the term in middle Byzantine times was in the military sphere: the holder of a strateia, or stratiotes (στρατιώτης), was obliged either to provide military service himself, or to provide money for the upkeep of a soldier, either as an individual or as a group/community (syndotai, "co-givers").
They also received pay (roga) and state-sponsored supplies (opsonion) for taking part in military expeditions and performing labour in public works.
[4] By the 11th century, the strateia had become a purely fiscal obligation, and no longer entailed any requirement for rendering personal military service.
[1] Consequently, instead of native Byzantine soldiers, mercenaries were increasingly hired by the proceeds from the strateia, a process accelerated after the late 11th century with the loss of the recruiting grounds of Asia Minor to the Seljuk Turks.