Denmark
- Sweyn Forkbeard ruled both Denmark and England from 1013 to 1014. He also ruled Norway from 999 to 1014.
- Cnut the Great ruled both Denmark and England from 1018 to 1035. He also ruled Norway 1028 to 1035.
- Harthacanute ruled both Denmark and England from 1040 to 1042.
- Personal union with Norway 1042–1047 under the Norwegian king Magnus I.
- Personal union with Norway from 1380 to 1814 (the Norwegian Riksråd was abolished in 1536).
- The Kalmar Union with Norway and Sweden from 1389/97 to 1521/23 (sometimes defunct).
- The kings of Denmark at the same time being dukes of Schleswig and Holstein 1460–1864 (Holstein being part of the Holy Roman Empire, now part of Germany).
- Personal union with Iceland from 1918 to 1944 when Iceland became a republic.
Read more about this topic: Personal Union