Although Janusz Radziwiłł (1612–1655), the Voivode of Vilnius and Grand Hetman of Lithuania, managed to acquire the Tauragė estate on the Lithuanian border with Prussia in the early 1650s, it was just before his death. His granddaughter Ludwika Karolina (1667–1695), who inherited the titles from his daughter Anna Maria (she passed away at an early age), was raised in Berlin and married the son of the Elector Friedrich Wilhelm (1620–1688) there in 1681. The Elector of Brandenburg decided to use this connection to renew his claim to the Tauragė estate (his father Georg Wilhelm had sold it in 1639). In 1688, Ludwika Karolina signed a document in Potsdam renouncing her inheritance rights to the Tauragė estate in favour of the Elector, and this was confirmed in 1691 by a court in Lithuania. Manfred Hellmann, who published a study on Prussian control of Tauragė in 1940, revealed the ambiguity that arose as a result: although Tauragė continued to belong to the Polish-Lithuanian Commonwealth, it was in fact controlled by Prussia, whose monarch became the owner of private land in the Commonwealth and had to pay the usual taxes and duties there. The article examines whether or not this political ambiguity was reflected in the depiction of the Tauragė estate on 18th-century maps. The research shows that this depiction was equally ambiguous: while some maps showed Tauragė as a part of Prussia, others did not emphasise the connection at all, continuing to show that the estate belonged to the Grand Duchy of Lithuania.