Count John IV of Nassau was a prominent nobleman in the 16th century, known for his role in the {Nassau} family, which played a significant part in the history of the {Netherlands}. He was born in 1536 and became the Count of Nassau-Dillenburg, inheriting a legacy of political influence and military leadership. Throughout his life, John IV was involved in various conflicts, including the {Eighty Years' War}, which was a revolt against Spanish rule in the {Low Countries}. His contributions to the {Protestant Reformation} and support for the {Dutch} cause helped shape the region's future, making him a notable figure in European history.