Complex sentence: They were taken to Denmark in 1521 and imprisoned in the infamous Blaatornet (Blue Tower) in Copenhagen-where she died of the plague in 1523, along with her two younger daughters Martha and Emerentia.
Split into simpler sentences: They were taken to Denmark in 1521 and imprisoned in the infamous Blaatornet (Blue Tower). She died of the plague in Blaatornet, Copenhagen, Denmark, in 1523, along with her two younger daughters Martha and Emerentia.