There has never been a real civil war in the Netherlands, although there were occasions of power struggles which nearly brought civil war.
The most remarkable war in Dutch history is of course the Eighty Years' War (1568-1648), in which full independence from Spain was fought for. The Oath of Abjuration ('Plakkaat van Verlatinghe') in 1581 was the formal declaration of independence. It stated the king is a servant of his people, and should respect their laws and traditions. When he no longer does this, the people have the right to choose another ruler. So the Dutch no longer recognized the king of Spain as their ruler. The Oath stood model for the American Declaration of Independence.
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