Aaron Alexandre (1766-1850) was the author of Encyclopedie des Echecs, the first book containing the collection of all opening variations then known. Published in 1837 (Alexander was then 71 years old), he introduced the algebraic notation and the castling symbols O-O and O-O-O. The rules of the game were published in four languages in this book. He also wrote Collection des Plus Beux Problems d’Echecs (The Beauties of Chess) in 1846, the first large compilation of chess problems and endgames, containing over 2,000 chess problems and solutions. He was a Jewish rabbi from Bavaria who moved to Paris in 1793. He went bankrupt with the hotel he owned, and took up chess to support himself. He was one of the operators of the automaton, the Turk.