On 20 February 1969, seven blind climbers and their four sighted companions completed the arduous trek to the 5,750m (18,865ft) crater summit of Mount Kilimanjaro, in Tanzania.
The group took nine hours to climb the last 914.4m (3,000ft), fighting against high winds and freezing temperatures, to where they observed a circling Fokker F27 Friendship aircraft dipping its wings in a salute to their achievement.
The object of the expedition - the brainchild of John Wilson, founder of the charity Sightsavers - was to "help create a new image of blindness in Africa" and demonstrate that "trained blind people have the mental and physical stamina to achieve exacting goals".
Eight embarked on the journey but on the evening of 19 February, after sleeping in a cave and making a steep and rocky climb that day, one of the climbers had to drop out.
"That day we had sore feet and one or two people started being sick from the altitude," said Geoffrey Salisbury, of the Royal Commonwealth Society for the Blind, as Sightsavers was then known.
"By now, we were all suffering from burned faces due to the direct rays of the Sun.
"We came across our first snow. I climbed the rocks and broke off a giant icicle and showed it to John Opio, who was suffering from a headache
"He was so startled that I think he forgot the pain.
"It was at this point that John Kisaka, from Tanzania, asked to drop out.
"He had climbed gallantly but was obviously not fit to go on."
The fittest trekkers were selected from hundreds of volunteers from Kenya, Uganda and Tanzania and underwent a two-week training programme, which included rope climbing, night camping and mastering the use of mountaineering equipment.
The trek was covered on front pages of African newspapers and all the trekkers received a hero's welcome. Three pairs of their worn out boots are displayed in the Ugandan National Museum.