Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck was born in Bazentin-le-Petit, Picardy, on August 1st 1744. He was the youngest of eleven children in rural France. The family had a strong military background, with several generations as officers in the French army. Some of Lamarck's older brothers made their careers in the military. His father wanted Jean to take a career in the church. However, Jean did not like the ministry, and quit his Jesuit college, bought himself a horse, and ran away to join the French army in their campaign near Fissinghausen, Germany after his father died.
In his military career, he quickly became a lieutenant in command of a garrison stationed at Monaco. It was peacetime, and the soldiers were indulging in some kind of physical game for relaxation, when one of the men lifted Lamarck off the ground by his head. This practical joke caused serious inflammation of the lymphatic glands in the neck, and Lamarck had to be taken to Paris for further treatment.
But surgery, if anything, only made the injury worse, and Lamarck was decommissioned. Because his military career was ruined, he fell back to studying the natural sciences which had been part of his instruction at college.
Lamarck began to study medicine in his spare time at the college. Nevertheless, he became more and more captivated with the natural sciences, finally abandoning medicine for the study of botany. With the help of a great botanist named Buffon, he published his Flore FranÃÂ§aise. This volume brought him great praise, and remained a standard work for many years. He was elected to the French Academy of Sciences the following year. He toured Europe searching for more plants and returned to become the keeper of the Royal herbarium at the Jardin des Plantes.