Question: What era did the husband of Dorothea of Brandenburg reign?
Related documents: [0]  [DOC] Dorothea of Brandenburg (1430/1431 – 10 November 1495) was Queen consort of Denmark (1445–1448 and 1449–1481), Norway (1445–1448 and 1450–1481), and Sweden (1447–1448 and 1457–1464) two times each by marriage to Christopher of Bavaria and Christian I of Denmark. She served as interim regent during the interregnum in 1448, and as regent in the absence of her second spouse during his reign. [END] 
[1]  [DOC] Christopher of Bavaria (26 February 1416 – 5/6 January 1448) was King of Denmark (1440–48, as Christopher III), Sweden (1441–48) and Norway (1442–48) during the era of the Kalmar Union. [END] 
Answer: 
Kalmar Union
Kalmar Union