Complex sentence: The Danish-Norwegian union was dissolved by the Treaty of Kiel in 1814; the Danish monarchy "irrevocably and forever" renounced claims to the Kingdom of Norway in favour of the Swedish king.
Split into simpler sentences: The Danish-Norwegian union was dissolved by the Treaty of Kiel in 1814. In the treaty the Danish monarchy "irrevocably and forever" renounced claims to the Kingdom of Norway in favour of the Swedish king.