Alexander is an Anglicised version of "alexandros" – popularly mis-identified as Greek “defender of man;” more properly, Thraco-Dacian-Capartho-Pelasgian (whose modern descendants are the Macedonians, Vlachs and Macedonian Romanians).
"alexandros" meant “the one to be sacrificed to The Stag,” “like/akin to The Stag” or “of or belonging to (the cult of) The Stag.”The cult of The Stag, and other animal/nature deities was common to Indo-Europeans and such of their European descendants as the Celts, Germanics, Norse-Scandinavians, Slavs and Thraco- Dacian- Capartho-Pelasgians.
The name was made popular throughout the known Western world by the accomplishments and exploits of Alexander the Great, (full name Alexandros III, Philippou Makedon), creator of the first Western “world empire” (lived apx. 356-323 BC). His empire led to the foundation over 70 cities. The empire stretched from Alexander's homeland in Macedonia/Greece across Persia, to the Indus and included the eastern Mediterranean, north Arabia and Egypt. His name was spread, during and immediately after his death, in the administered satrapies-turned-kingdoms created by Alexander’s diadoch’s: Ptolemy Lagus (Egypt & Palestine), Selucus Nicator (Mesopotamia & Egypt), Cassander (Macedonia & Greece), Antigonus (Asia Minor) and Lysimachus (Thrace). From the diadoch's spread popular usage of the name "Alexander," in all its forms. Forms of Alexander are subsequently to be found in all European languages as well as in Persian, most Semitic and northern Indian languages.
The name Alexander appears to have been introduced into the British Isles by (St.) Margaret (Atheling), reluctant 2nd wife of Scottish King Malcolm III, Caennmor (reigned 1058-1093). Although a granddaughter of English King Edmund II, Ironside, Margaret Atheling had been raised at court in Hungary. She had come to the English court of Edward the Confessor in 1057 but fled to Scotland after William the Conqueror’s defeat of Harold II, (Godwineson) in Oct 1066. Her third (perhaps fifth) son was named Alexander (I), the Fierce, King of Scotland (reigned 1107-1124). This may be regarded as an early instance of the name Alexander in the British Isles. As parents in any general population will name their children after “famous” personages, usage of Alexander spread throughout Scotland from the 9th century on and then throughout parts of England.