What medieval group controlled parts of the Baltic with crusades against pagans?

The story behind the answer

They were a German crusading order that shifted from the Holy Land to the Baltic in the 13th century, invited by Duke Konrad of Masovia to fight pagan Prussians. Through the Northern Crusades they carved out a monastic state in Prussia and Livonia, building fortress networks and controlling key Baltic trade routes while enforcing conversion.

At their height they ruled from massive brick castles like Marienburg (Malbork). Their dominance waned after the 1410 Battle of Grunwald/Tannenberg, when a Polish‑Lithuanian coalition shattered their army. In 1525 their Prussian lands were secularized into the Duchy of Prussia, but their campaigns profoundly reshaped the Baltic’s demographics, urban landscape, and political borders for centuries.