King Valdemar IV, also known as Valdemar the Victorious, was a significant monarch of Denmark who reigned from 1340 to 1375. He is remembered for his efforts to strengthen the Danish kingdom and expand its territories. Valdemar IV was known for his military campaigns, particularly against Sweden and Norway, which helped to solidify Denmark's influence in the region. During his reign, Valdemar IV also focused on internal governance, promoting trade and improving the economy. His leadership contributed to the development of Copenhagen as a vital city. Valdemar IV's legacy is marked by his attempts to unify the Scandinavian countries under Danish rule.