On March 20, 1800, Alessandro Volta announced the invention of the voltaic pile—the first true battery—in a letter to Joseph Banks, president of the Royal Society of London. By stacking zinc and copper discs separated by saltwater-soaked cloth, he generated a continuous electrical current, proving that electricity could be produced chemically. This breakthrough laid the foundation for modern battery technology, shaping advancements in electromagnetism, communication, and energy storage. Volta's work remains a cornerstone of electrical science, influencing everything from early telegraphs to today's rechargeable batteries.