Great Moravi, also Moravia, Great Moravian Empire, or Moravian Knezate, is the first West Slavic state.

Its core territories are located on the northern Morava River along the present-day border of the Czech Republic and Slovakia.

Theories of a Great Moravia situated in the region of the southern Great Morava River have not widely been accepted.

The exact date of the founding of the Moravian state is controversial, but it is supposed that the state building process was completed in the early 830s under Mojmir I (r. 820s/830s–846), who is the first known Moravian ruler.Mojmir and his successor, Rastislav (r. 846–870) initially acknowledge the Carolingian monarchs' suzerainty, but their fights for independence cause a series of armed conflicts with East Francia from the 840s.

Moravia reaches its largest territorial extent under Svatopluk I (r. 870–894), who is occasionally styled as king in contemporaneous sources.

Although his empire's borders cannot exactly be determined, he controls, in addition to the core territories of Moravia, other neighboring regions (including Bohemia, and parts of present-day Hungary and Poland) for a longer or shorter period during his reign.

Separatism and internal conflicts emerging after Svatopluk's death contribute to the fall of Moravia, which is overrun by the Hungarians.

The exact date of Moravia's collapse is unknown, but it occurs in the period between 902 and 907.Moravia experiences significant cultural development after the 863 arrival of the mission of Saints Cyril and Methodius, initiated by Prince Rastislav, which introduces a system of writing (Glagolitic alphabet) and Slavonic liturgy, the latter eventually formally approved by Pope Adrian II.

The Glagolitic script and its successor Cyrillic are disseminated to other Slavic countries (particularly Balkan and Kievan Rus'), charting a new path in their cultural development.