The city of Gavle received its charter during which era?
Gävle:  It is the oldest city in the historical Norrland (Sweden's Northern Lands), having received its charter in 1446 from Christopher of Bavaria. Christopher of Bavaria: 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.
era of the Kalmar Union