Dutch King Willem-Alexander apologised to Indonesia on Tuesday for "excessive violence" during the former colony's independence struggle in the 1940s.
The king made the remarks during a state visit to the country with Queen Maxima after a ceremony with Indonesian President Joko Widodo in the capital Jakarta.
Indonesia declared its independence on August 17, 1945 following a brief wartime occupation by the Japanese and several hundred years as a Dutch colony.
"The past cannot be erased, and will have to be acknowledged by each generation in turn," the king said in a joint statement.
In the years after the independence proclamation "a painful separation followed that cost many lives... I would like to express my regret and apologise for excessive violence on the part of the Dutch in those years," he added.
"I do so in the full realisation that the pain and sorrow of the families affected continue to be felt today."