Old Bishop's Palace in Oslo
Oslo Ladegård — the 1725 Baroque manor built on the site of the old palace — Mahlum, via Wikimedia Commons · Public domain
Construction began around 1210 under Bishop Nikolas Arnesson on the site of a 12th-century wooden predecessor, eventually growing into a fortified stone complex connected to the neighbouring Hallvard's Cathedral by a wooden bridge from its tower. It was here, just after King Håkon V's death in 1319, that the first union agreement between Norway and Sweden was signed. Swedish attacks damaged the palace in 1523, and after the Reformation in 1537 much of it was demolished. What stands on the site today is Oslo Ladegård, a Baroque manor house built in 1725 directly on the medieval palace's foundations — the closest thing to a surviving trace of the original bishop's residence.
