Photo of Compass of Louis de Boisot - Public domain dedication

Louis de Boisot was an admiral from Zeeland. He is chiefly remembered for leading the forces that breached the dikes around Leiden during the Spanish siege of the city. The rising water forced the Spaniards to flee, and Boisot’s flotilla was able to sail into the city on 3 October 1574. This compass bears his family arms and is reputed to have belonged to him.