Complex sentence: From rock climbing he expanded into mountaineering with trips to the Alps where ascents included the "Bonatti Pillar" of the Dru and the first ascent with Chris Bonington, Jan Długosz and Ian Clough of the Central Pillar of Freney on Mount Blanc.
Split into simpler sentences: From rock climbing he expanded into mountaineering with trips to the Alps. Ascents in the alps included the "Bonatti Pillar" of the Dru and the first ascent along with Chris Bonington, Jan Długosz and Ian Clough of the Central Pillar of Freney on Mount Blanc.