Magnesia may refer to: * Magnesia (hypothetical city), a future colony of Knossos, imagined in Plato's ''

Laws Law is a set of rules that are created and are law enforcement, enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. ...

'' *

Magnesia (regional unit) Magnesia ( el, Μαγνησία, ''Magnisía'', , Ancient Greek: ''Magnēsía'', deriving from the tribe name ''Magnetes'') is one of the regional units of Greece. It is part of the region of Thessaly. Its capital is the city of Volos. About 70% o ...

, the southeastern area of Thessaly in central Greece *

Ancient Magnesia Anciently, Magnesia ( grc, Μαγνησία) was a region of Ancient Greece, eventually absorbed by ancient Thessaly. Originally inhabited by the Magnetes (Μάγνητες), Magnesia was the long and narrow slip of country between Mounts Ossa a ...

, a historical region of Greece with borders differing from the modern regional unit *

Magnesia ad Sipylum Magnesia Sipylum ( el, Mαγνησία ἡ πρὸς Σιπύλῳ or ; modern Manisa, Turkey) was a city of Lydia, situated about 65 km northeast of Smyrna (now İzmir) on the river Hermus (now Gediz) at the foot of Mount Sipylus. The cit ...

, a city of Lydia, now Manisa in Turkey **

Battle of Magnesia The Battle of Magnesia took place in either December 190 or January 189 BC. It was fought as part of the Roman–Seleucid War, pitting forces of the Roman Republic led by the consul Lucius Cornelius Scipio Asiaticus and the allied Kingdom of Pe ...

, 190 BC, the concluding battle of the Roman–Seleucid War *

Magnesia on the Maeander Magnesia or Magnesia on the Maeander ( grc, Μαγνησία ἡ πρὸς Μαιάνδρῳ or ; la, Magnesia ad Maeandrum) was an ancient Greek city in Ionia, considerable in size, at an important location commercially and strategically in th ...

, an ancient Greek city in Anatolia *

Magnesia Prefecture Magnesia Prefecture ( el, Νομός Μαγνησίας) was one of the prefectures of Greece. Its capital was Volos. It was established in 1899 from the Larissa Prefecture. The prefecture was disbanded on 1 January 2011 by the Kallikratis progra ...

, a former prefecture of Greece

Chemistry

Magnesium oxide Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

Periclase Periclase is a magnesium mineral that occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. It is a cubic form of magnesium oxide ( Mg O). In nature it usually forms a solid solution with wüstit ...

or magnesia, a natural mineral of magnesium oxide

Chemistry

See also