William of Orange, also known as William the Silent (1533-1584) founded the Dutch noble house of Orange-Nassau and spent most of his life enmeshed in the struggle for Dutch independence from their Spanish overlords. Over the course of William's life many tried to assassinate him to further the Spanish cause. On one notable occasion, during a 1572 counteroffensive campaign in France, William lay sleeping in his tent, but his dog Pompey heard someone approaching. Though he barked and scratched, Pompey couldn't rouse his master. Finally he jumped on his face, William awoke, and the would-be assassins were routed.
It's said that Pompey was a pug, and that this loyal act led to the House of Orange's fondness for pugs - a fondness that rolled over to the British royal family with William and Mary. However, William the Silent's tomb includes a sleeping dog at the feet of his reclining figure in honor of the good Pompey, and that dog does not look like a pug. Some older books refer to Pompey as a spaniel, which is what that dog resembles. It's more than possible Pompey was a Kooikerhondje, or "Duck decoy dog." The link takes you to an interesting article on this cute, petite breed. There's a photo of William's tomb; it's terrible, frankly, but I think you'll agree that's not a pug.
Interested in the twists and turns of William the Silent's life? Here's a Wikipedia page.