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In page Livonia:

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In the next phase of the conflict, in 1577, Ivan IV took advantage of the Commonwealth's internal strife (called the war against Gdańsk in Polish historiography), and during the reign of Stefan Batory in Poland, invaded Livonia, quickly taking almost the entire territory, with the exception of Riga and Reval. In 1578, Magnus of Livonia recognized the sovereignty of the Polish–Lithuanian Commonwealth (not ratified by the Sejm of Poland-Lithuania, nor recognized by Denmark). The Kingdom of Livonia was beaten back by Muscovy on all fronts. In 1578, Magnus of Livonia retired to The Bishopric of Courland, and his brother all but gave up the land in Livonia.[citation needed]