Terra Mariana in the context of "State of the Teutonic Order"

Livonia, known in earlier records as Livland, is a historical region on the eastern shores of the Baltic Sea. It is named after the Livonians, who lived on the shores of present-day Latvia.

By the end of the 13th century, the name was extended to most of present-day Estonia and Latvia, which the Livonian Brothers of the Sword had conquered during the Livonian Crusade (1193–1290). Medieval Livonia, or Terra Mariana, reached its greatest extent after the Saint George's Night Uprising (1343–1345), which forced Denmark to sell the Duchy of Estonia (northern Estonia conquered by Denmark in the 13th century) to the State of the Teutonic Order in 1346. Livonia, as understood after the retreat of Denmark in 1346, bordered on the Gulf of Finland in the north, Lake Peipus and Russia to the east, and Lithuania to the south.

The Baltic German nobility was a privileged social class in the territories of modern-day Estonia and Latvia. It existed continuously from the Northern Crusades and the medieval foundation of Terra Mariana.

Most of the nobility consisted of Baltic Germans, but with the changing political landscape over the centuries, Polish, Swedish, Russian, Danish, and even Scottish families also became part of the nobility, just as Baltic German families re-settled in locations such as the Swedish and Russian Empires. The nobility of Lithuania is for historical, social and ethnic reasons separated from the German-dominated nobility of Estonia and Latvia.

The Livonian War (1558–1583) concerned control of Old Livonia (in the territory of present-day Estonia and Latvia). The Tsardom of Russia faced a varying coalition of the Dano-Norwegian Realm, the Kingdom of Sweden, and the Union (later Commonwealth) of the Grand Duchy of Lithuania and the Kingdom of Poland.

From 1558 to 1578, Russia dominated the region with early military successes at Dorpat (Tartu) and Narva. The Russian dissolution of the Livonian Confederation brought Poland–Lithuania into the conflict, and Sweden and Denmark-Norway intervened between 1559 and 1561. Swedish Estonia was established despite constant invasion from Russia, and Frederick II of Denmark-Norway bought the old Bishopric of Ösel–Wiek, which he placed under the control of his brother Magnus of Holstein. Magnus attempted to expand his Livonian holdings to establish the Russian vassal state, the Kingdom of Livonia, which nominally existed until his defection in 1576.