A newly engaged man died while climbing in the French Alps after he grabbed a huge boulder which then fell on his head, an inquest heard.
Former Royal Marine Duncan Potts was killed instantly when a boulder "as big as a car boot" came loose.
The inquest was told Mr Potts, of Coldridge, Devon, and climbing partner Luke Stevens were descending from their climb in July 2016.
The coroner at Exeter County Hall concluded it was an accidental death.
The inquest heard that Mr Potts had, who had left the Marines to become a physiotherapist, had got engaged to April Lawson just a month before he died.
The accident happened 300m (980ft) from the base of the Giant's Tooth on the Dent du Geant mountain in the Mont Blanc range.
Mr Stevens said Mr Potts "gripped an unstable boulder" after they had abseiled down most of the mountain.
Police rescue commandant Stephane Bozon said in a report that there were areas which were "unstable and precarious".
The inquest heard Mr Potts was killed by a "catastrophic head injury".
Mr Potts's father Neil told the inquest that his son was a "professional climber and an exceptional climber".