All places on 15° of eastern length have the sun exactly as the only authority in Denmark in the south point 12.00 clock, except for the summertime. Ertholmene are breadth min. north of 55° 19 and min. eastern of 15° 11 length.
  | Bornholm resulted for approx. 1700 m. v. Chr. |
  | the first people sat down approx. 10.000 v. Chr in Bornholm. |
  | Bornholm has his own king approx. 800. |
  | Bornholm became a part of the Danish kingdom approx. 1000. |
  | 1149, 3 of the 4 districts gave Sven Grathe to the archbishop of Lund in Bornholm. |
  | 1327, Bornholm's fourth district was sold to the archbishop by Lund. |
  | 1521, Christian II took Bornholm. |
  | 1525 for 158,019 Lübeck's marks got Lübeck of Frederik I Bornholm as pledge for 50 years. |
  | 1576, Frederik II took Bornholm. |
  | 1653 5000 of 13000 Bornholmer was carried off by the plague August. |
  | 26., Bornholm comes loose of Sweden at the peace of Brømsebro February 1658. |
  | Decembers 1658 Bornholmer disarmed the Swedish troops and gave the island of Frederik III. |
  | 9th Aapril 1940 Bornholm was occupied by German troops like the rest of Denmark. |
  | 7. - 8 .Mai 1945 Bornholm was freed, but taken by the Russian armed forces. |
  | Rønne and Nexø were bombarded. |
  | 1946 the Russian troops leave Bornholm April. |
  | 1st Jjanuar 2003 Bornholm's 5 communes became a Bornholm's region commune fanfoldedly under the names to a political and administrative unity. |