Moira may refer to:
Moira (Greek: μοῖρα, pronounced míra, plural μοῖραι) is a Greek term for a military formation. Etymologically, it is derived from the roots *μερ- and *μορ-, which mean "to part". Moira therefore means "a part, a division", and is cognate with the similar term meros. In the Byzantine period, it was used to denote brigade or division-sized commands, while in the modern Greek military, it is used by some branches to designate battalion-sized units.
In the late 6th to early 7th century, the Late Roman military system, which was still in use by the East Roman or Byzantine Empire, went through a process of martial transformations that culminated with the establishment of the new military-administrative theme system in the 680s. Every major division, called a thema (Greek: θέμα), was further divided into tourmai while each tourma was divided into moirai or droungoi, which in turn were composed of several banda. Thus each moira or droungos was the analogue of a modern regiment or brigade, initially circa 1000 men strong (and hence also referred to as a chiliarchia), although on occasion it could rise to 3000 men, and Emperor Leo VI the Wise (r. 886–912) is recorded as having established droungoi of only 400 men for the new smaller themes.
In Greek mythology, the Moirai or Moerae /ˈmɪrˌiː/ or /ˈmiːˌriː/ (Ancient Greek: Μοῖραι, "apportioners"), often known in English as the Fates (Latin: Fatae), were the white-robed incarnations of destiny; their Roman equivalent was the Parcae (euphemistically the "sparing ones"). Their number became fixed at three: Clotho (spinner), Lachesis (allotter) and Atropos (unturnable).
They controlled the mother thread of lifestyle of every mortal from birth to death. They were independent, at the helm of necessity, directed fate, and watched that the fate assigned to every being by eternal laws might take its course without obstruction. The gods and men had to submit to them, although Zeus's relationship with them is a matter of debate: some sources say he is the only one who can command them (the Zeus Moiragetes), yet others suggest he was also bound to the Moirai's dictates. In the Homeric poems Moira or Aisa, is related with the limit and end of life, and Zeus appears as the guider of destiny. In the Theogony of Hesiod, the three Moirai are personified, and are acting over the gods. Later they are daughters of Zeus and Themis, who was the embodiment of divine order and law. In Plato's Republic the Three Fates are daughters of Ananke (necessity).