In 1814, Denmark was penalized for its support of Napoleon by giving Norway to Sweden. Before the transition was carried out, Norway declared itself independent on May 17, 1814. A degree of independence was retained even after Norway became subject to the Swedish Crown.
In 1905, on May 17, Norway declared its complete independence.
In 2016, six of us traveled to Norway to observe the national day of Norway, or as they like to call it Nasjonaldagen.
Their hot dogs look like this https://ichef.bbci.co.uk/news/1024/branded_news/B80F/production/_106591174_p077fz1m.jpg
best explained in this https://www.bbc.com/news/av/world-europe-48054846/why-norway-loves-its-own-take-on-the-hot-dog BBC exposé.
My best pictures: