Carrel first attempted to climb the Matterhorn's Lion Ridge in 1857—by which time the mountain was the tallest unclimbed peak in the Alps—with his uncle and Amé Gorret. In the early 1860s, Carrel made numerous attempts to climb the Matterhorn, often in the same party as Edward Whymper and John Tyndall, and at other times competing against them to reach the summit first. Carrel had agreed to accompany Whymper on his ascent of the Swiss side in 1865, but withdrew at the last minute when he was recruited by Felice Giordano on behalf of the Italian Alpine Club to lead an Italian party up the Italian side at the same time. Ultimately, Whymper's party outclimbed the Italians and reached the summit on 14 July 1865, marking the first ascent of the Matterhorn. Carrel and his Italian party successfully summited the Matterhorn three days later.