The Strasbourg Agreement of 27 August 1675 is the first international agreement banning the use of chemical weapons. The treaty was signed between France and the Holy Roman Empire, and was created in response to the use of poisoned bullets. The use of this weaponry was preceded by Leonardo da Vinci's invention of arsenic and sulfur-packed shells that can be fired against ships. These weapons had been used by Christoph Bernhard von Galen, Bishop of Munster, in the Siege of Groningen (1672) – thus provoking the Strasbourg Agreement between the belligerents of the Franco-Dutch War.