The game that most people call tennis is the direct descendant of what is now known as real tennis or royal tennis (which continues to be played today as a separate sport with more complex rules). Most of the rules of the game commonly known as tennis derive from real or royal tennis. It is reasonable to see both sports as variations of the same game. Most historians believe that tennis originated in the monastic cloisters in northern France in the 12th century, but the ball was then struck with the palm of the hand hence the name jeu de paume ("game of the palm"). It was not until the 16th century that rackets came into use, and the game began to be called "tennis." It was popular in England and France and Henry VIII of England was a big fan of the game, now referred to as real tennis.

Many original tennis courts remain, including courts at Oxford, Cambridge and Hampton Court Palace. Many of the French courts were decommissioned with the terror that accompanied the French Revolution. The Tennis Court Oath (Serment du Jeu de Paume) was a pivotal event during the first days of the French Revolution. The Oath was a pledge signed by 576 of the 577 members from the Third Estate who were locked out of a meeting of the Estates-General on 20 June 1789. Any history of tennis that ignores its origins in the game that was (and is still in certain circles) known as tennis until "lawn tennis" became popular in the late nineteenth century is inaccurate.