Jean-Baptiste was the 11th child of Philippe Jacques de Monet de La Marck and Marie-Françoise de Fontaine de Chuignolles. His parents were nobles, but they were not well-off. His parents wanted him to become a priest. Starting at age eleven, he attended a Jesuit school in Amiens. After his father's death in 1759, Jean-Baptiste joined the army. Lamarck fought in the Pomeranian War with Prussia, and was awarded a medal for bravery on the battlefield. During his service, he was stationed in different forts in France, mostly at the eastern border, and the Mediterranean coast. At his post in Monaco, Lamarck became interested in natural history and resolved to study medicine. In 1766, he was injured. He retired from the army in 1768 and returned to his medical studies. He worked at a bank in Paris. From 1770 to 1774, he studied medicine at the university, but did not finish his studies with a degree. During this time, he met some of the well-known scientists of his day, such as the botanists Bernard and Antoine-Laurent de Jussieu, and the naturalist Buffon.