Willem van Oranje-Nassau is also known as Willem the Silent or Willem the Taciturn. He was a statesman and army leader who had a key role in the start of the 80-year war with Spain which resulted in the formal independence of the United Provinces in 1648. He's the ancestor of the Dutch monarchy and dubbed 'Father of the Fatherland'.
The reasons he rebelled against the Spanish interference with Dutch governing, were multiple: he wanted more political power for himself and other Dutch nobility, he was a huge proponent of religious freedom and thus against the Spanish Inquisition, and lastly he wanted Spanish troops out of the region.
Willem the First was eventually shot at close range and killed in his hometown of Delft by catholic Balthasar Gerard. The bullet holes from the murder have been preserved. They're actually huge; bullets back then were as large as small canon bombs.