Jean-Victor Poncelet was a French engineer and mathematician born on July 1, 1788. He is best known for his contributions to projective geometry, a branch of mathematics that studies geometric properties that are invariant under projection. Poncelet's work laid the foundation for many modern concepts in geometry and influenced later mathematicians. In addition to his mathematical achievements, Poncelet served in the French military during the Napoleonic Wars. After being captured, he spent time in Russia, where he developed many of his ideas. His most notable publication, Traité des propriétés projectives des figures, was published in 1822 and significantly advanced the field of geometry.