[1] Steinvikholm castle became a powerful fortification by the time it was built, and it is the largest construction raised in the Norwegian middle ages.
Construction started after his return from a meeting with the Pope in Rome, presumably in anticipation of impending military-religious conflict.
[5] As Archbishop Engelbrektsson's resistance to the encroachment of Danish rule escalated, first with King Frederick I of Denmark and his successor King Christian III of Denmark, Steinvikholm Castle and Nidarholm Abbey became the Roman Catholic Church's military strongholds in Norway.
In April 1537, the Danish-Norwegian Reformation succeeded in driving the archbishop from the castle into exile at Lier in the Netherlands (now in Belgium), where he died on 7 February 1538.
Steinvikholm Fort is owned and operated today by the Society for the Preservation of Norwegian Ancient Monuments (Fortidsminneforeningen).