ROME — Achille Compag-noni, one of the first two men to reach the summit of K2, the world’s second-highest peak and among the most dangerous, died Wednesday in Aosta, in northeastern Italy. He was 94.

His wife, Elda Compagnoni Mossini, confirmed his death.

Compagnoni and his fellow climber Lino Lacedelli were part of an Italian team that conquered the mountain on July 31, 1954. K2 is in the border region of northern Pakistan and China. The expedition, of more than a dozen members, had been organized by the explorer and geologist Ardito Desio, who died in 2001.

It “was one of the last acts of heroic mountaineering,” Rein-hold Messner, a renowned Italian mountain climber, told the news agency ANSA this week. “Compagnoni,” Messner added, “was a physically strong climber, with a lot of heart and big lungs.”

Rising about 28,250 feet, K2 is surpassed in height only by Mount Everest (more than 29,000 feet), 800 miles to the southeast. But K2, towering like a steep pyramid in the Karakoram range, is known as a more treacherous mountain to scale. Dozens of climbers have died on its harrowing, often near-vertical slopes, many on the way down. In August 2008, 11 climbers were killed in one of the worst disasters in mountain-climbing history.

The name K2 was a preliminary designation given to the peak in the Great Trigonometrical Survey of India in the 19th century. The name stuck, but mountain climbers have also called K2 the Savage Mountain; locally it is known as Chogori, variously translated as king of mountains or magnificent mountain.

The Italians’ moment of glory came when competition to conquer the Himalayas was fierce, said Agostino Da Polenza of the Everest-K2-CNR Committee, a mountain research group in Italy. Less than a year earlier, Sir Edmund Hillary and Tenzing Norgay had become the first to reach the summit of Everest.

The K2 ascent became a source of national pride; the climbers were decorated by both the Italian and the Pakistani governments.

“The Italians managed to do it first,” Da Polenza said, “and as the country was just coming out of the war, this conquest became a symbol of rebirth and hope.”

Compagnoni was born Sept. 26, 1914, in Santa Caterina Valfurva, a mountainous area of Lombardy. “As a young boy, he dreamed of being a guide, of exploring the mountains,” his wife said. “His passion was stoked because he lived in these places.”

He served in the Alpine corps of the Italian military and won several cross-country ski championships. After World War II, he moved to Cervinia, where he built a home and worked as a ski instructor and an alpine guide before being called by Desio to climb K2.