June 15 - The first human blood transfusion is administered by Dr. Jean-Baptiste Denys . He transfuses the blood of a sheep to a 15-year old boy. (Though this operation is a success, a later patient dies from the procedure and Denys is accused of murder).
June 20 – Dutch troops attack Royal Navy ships in London and Chatham and burn them.
Louis XIV of France abolishes the Livre Parisis (Paris Pound) in favor of the much more widely used Livre Tournois (Tours Pound). He also designates Gabriel-Nicolas de la Reynie as first chief of "police" of Paris.