Former Gurkha and Special Boat Service soldier, an elite special forces unit of the United Kingdom's Royal Navy, Purja started his mission, Project Possible, earlier in the spring to climb all 14 of the world's highest peaks within seven months.
"It has been a gruelling, but humbling six months, and I hope to have proven that anything is possible with some determination, self-belief and positivity", the 36-year-old said.
A Nepalese mountaineer yesterday smashed the speed record for summiting the world's 14 highest peaks, racing up all "8000ers" in just six months and six days, organizers said.
"MISSION ACHIEVED!" said Nirmal Purja from the summit of Shishapangma, according a tweet on Purja's Twitter handle.
This photo taken on May 22 by Nirmal Purja shows heavy traffic of mountain climbers lining up to stand at the summit of Mount Everest. South Korean Kim Chang-ho completed the challenge one month faster - although unlike Kukuczka and Purja, he never used supplementary oxygen.
Nirmal Purja on Tuesday completed his ascent of the world's 14 tallest mountains, knocking almost seven-and-a-half years off the previous record.
Twenty-three days later he was standing atop Broad Peak, his fifth and final mountain of the second phase.
Purja's photo of a long line of climbers just below the Mount Everest summit was widely circulated on social media in May.
He was awarded an MBE in 2016 for his outstanding achievement on high-altitude mountaineering and holds multiple world records for fastest mountain climbing times. He broke his own previous world record for the same three peaks, taking five days in 2017.
Chinese authorities had granted Purja and his team a special permit to scale Shishapangma at the request of the Nepali government.
He said then he wanted his feats to inspire the next generation of Nepalese climbers to break his records.
Mingma Sherpa, Chairman of Seven Summit Treks, the agency handling Purja's climb, told the Post that Purja made it to the summit at 8:58 am local time.
During the course of their climbs, Purja and his team members say they rescued at least three other mountaineers who were in trouble.