The Spanish Opening is one of the absolutely oldest. It is named after the Spanish priest Ruy López de Segura, who in 1561 presented his analyses on this way of starting the game in a book. But even today the Spanish can be seen in many games of top players and it is quite clearly the most important of the Open Games. Not only does White develop his bishop, he also immediately puts pressure on the black e5-pawn. Whereas previously 3...a6 was almost obligatory, nowadays 3...Nf6 – the Berlin Defence – is favoured.