Christian IV of Denmark

Christian IV (12 April 1577 – 28 February 1648) was King of Denmark and Norway and Duke of Holstein and Schleswig from 1588 to 1648. His 59-year reign is the longest of Danish monarchs, and of Scandinavian monarchies.
A member of the House of Oldenburg, Christian began his personal rule of Denmark in 1596 at the age of 19. He is remembered as one of the most popular, ambitious, and proactive Danish kings, having initiated many reforms and projects. Christian IV obtained for his kingdom a level of stability and wealth that was virtually unmatched elsewhere in Europe. He engaged Denmark in numerous wars, most notably the Thirty Years' War (1618–48), which devastated much of Germany, undermined the Danish economy, and cost Denmark some of its conquered territories. He rebuilt and renamed the Norwegian capital Oslo as Christiania after himself, a name used until 1925.
== Early Years ==
=== Birth and Family ===
Christian was born at Frederiksborg Castle in Denmark on 12 April 1577 as the third child and eldest son of King Frederick II of Denmark–Norway and Sofie of Mecklenburg-Schwerin. He was descended, through his mother's side, from king John of Denmark, and was thus the first descendant of King John to assume the crown since the deposition of King Christian II.
At the time, Denmark was still an elective monarchy, so in spite of being the eldest son Christian was not automatically heir to the throne. However, in 1580, at the age of 3, his father had him elected Prince-Elect and successor to the throne.