I n the early hours of 2 June 1953, guests at the Pen-Y-Gwryd hotel in the heart of Eryri (Snowdonia) were woken from their sleep by the sound of footsteps running down the corridor outside their rooms. The commotion was followed by gleeful shouting and the sound of champagne corks popping. A late-night telephone call to the hotel’s owner had moments earlier confirmed that Edmund Hillary and Tenzing Norgay had successfully summited Mount Everest. It had taken two days for the news to travel from the Himalayas to London. Serendipitously, news of the historic achievement coincided with the coronation of Queen Elizabeth II later that day.

In the days and weeks that followed, the two mountaineers were feted across the front pages of newspapers around the world. Posing awkwardly for the cameras, their beaming smiles shone out of frost-burnt faces.…