Three of these north faces—the Eiger, the Matterhorn and the Grandes Jorasses—are considerably harder to climb than the others. This led to their becoming known as 'the Trilogy'. The first to climb these three faces within a year was the Austrian Leo Schlömmer, from the summer of 1961 to the summer of 1962. Ivano Ghirardini was the first man to climb the Trilogy in winter, solo (1977-78), and Catherine Destivelle was the first woman (1992-93-94). With the introduction of the concept of enchainment, the next challenge was to climb all three faces in one outing, a race eventually won by Christophe Profit, who achieved the feat between 11-12 March 1987 in a time of 24 hours.