Ruy Lopez that after the common retreat 4.Ba4, Black will have the possibility of breaking a future pin on his by playing ...b5. White must take some care not to fall into the Ruy Lopez, Noah's Ark Trap, in which Black traps White's on the b3-square with a ...a6, ...b5, and ...c4 pawn advance on the . Ercole del Rio, in his 1750 treatise "Sopra il giuoco degli Scacchi, Osservazioni pratiche dell'anonimo Modenese" (On the game of Chess, practical Observations by an anonymous Modenese), was the first author to mention 3...a6. However, the move became popular after it was played by Paul
Ruy Blas and the Blasé Roué and Don Caesar are introduced to the royal palace in the capacity of strolling players. Don Salluste, a corrupt court official, has private reasons to wish to humiliate the Queen, and he persuades Ruy and Caesar to disguise themselves as women and apply for posts in the royal household. They are accepted, and Salluste then accuses the Queen of smuggling men into her private apartments, disguised as women. Ruy and Caesar are arrested and jailed. Ruy and Caesar find that their imprisonment is extraordinarily luxurious, but despite its attractions they escape, with the connivance of the Queen. Ruy and Caesar