May 17th  - Constitution Day

In the 14th century Norway, Sweden, and Denmark were members of the Union of Kalmar. In 1459, Sweden broke away from the Union and as a result Norway  became closely linked  to Denmark.
During the 18th century, Danish control over Norway relaxed and at the end of the Napoleonic Wars,  the Treaty of Kiel transferred Norway to Sweden. Norwegians refused to accept the change, as they wanted independence. The Swedish army invaded Norway, but thankfully an agreement was reached. On the 17th May 1814, the Norwegian constitution was written at Eidsvold, Norway. Norwegians were allowed  to retain their constitution on condition that the Swedish king was to remain king of Norway.
In 1905 the union with Sweden peacefully dissolved, and the Danish prince Carl (Haakon VII) was invited by the Norwegian people to become king. of Norway.