Alexius is the Latinized form of the Greek name Ἀλέξιος (Alexios), a derivative of Ἄλεξις (see Alexis). The name derives from the Greek verb ἀλέξω (alexo), meaning "to defend" or "to help", giving Alexius the overall meaning of "defender" or "helper". It is one of the most ancient attested Greek names, appearing in Linear B tablets as a-re-ke-se-u (KN Df 1229 and MY Fu 718), showcasing its deep roots in Greek onomastics. Notable Bearers in History In the Byzantine Empire, the name Alexius was particularly prominent, borne by five emperors of the Komnenian and subsequent dynasties: Alexios I Komnenos (1048–1118), who restored the empire after the Battle of Manzikert Alexios II Komnenos (1167–1183), the young, short-reigning son of Manuel I Alexios III Angelos, emperor during the Fourth Crusade Alexios IV Angelos, also deposed during the crusader sack Alexios V Doukas (Mourtzouphlos), the last Byzantine emperor of the period The name also appeared in the Empire of Trebizond, with a line of Alexios I through Alexios V, reflecting its enduring popularity among Byzantine aristocrats. In Eastern Europe, the name Alexius was adopted by the Russian Tsar Alexius Mikhailovich (1629–1676), the second Romanov ruler, whose reign marked significant territorial expansion and legal reform. Religious and Cultural Significance Among Eastern Christian saints, Saint Alexius of Edessa (or Alexius the Man of God) is especially venerated. According to legend, he lived as an anonymous beggar in his father's house after visiting Rome. The name also spread to Western Europe through medieval Latin usage. Variants and Derivatives Alexius shares etymological overlap with Alexander: both derive from alexo (defend) + verbal endings. Its ancient Greek form Alexios (Αλέξιος) commonly takes modern cognates like Aleksi (Georgian, Finnish) and Alexej (Slovak, Russian). The dialectal variants Aleix (Catalan) and Aleš (Slovene) also exist. The female form Alexia (Greek: Αλεξία) remains popular alongside modern English Alexis.