After the death of Duke Ernest the Pious of Saxe-Gotha-Altenburg in 1675, the Duchy was broken up into seven pieces because he wanted all his sons to be entitled to inherit.
One of them was Ernest. He was the second youngest son and the first Duke and Founder of the Saxe-Hildburghausen line.
The blood line was also inherited here as far as Emma of Waldeck and Pyrmont, who became the Queen of the Netherlands through her marriage to William III in 1879. She is the mother of Wilhelmina of the Netherlands, grandmother to Juliana, also called “Mother of the Nation” as the oldest member of the House of Orange-Nassau, and the great-grandmother of Princess Beatrix, the former Queen of the Netherlands.
Beatrix is in turn the mother of today’s King of the Netherlands, Willem-Alexander. He took over the office in 2013.