Diane is the French form of Diana — Roman goddess of the hunt. Diane de Poitiers (1500-1566) was the French noblewoman and lifelong mistress of King Henry II of France — twenty years his senior, she effectively shared power with the queen Catherine de' Medici. A famed beauty (whose reported daily golden-elixir routine fed the myth of her perpetual youth), she commissioned the Château d'Anet and is the model for some of the Fontainebleau School's most famous paintings. Among the most influential royal mistresses in French history.
Subject of countless French Renaissance paintings and biographies.
Diane does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Diane reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.