Adriana Brownlee, 23, completed her task by reaching the summit of Shishapangma in Tibet on 9 October and described her final push as an emotional one.

"I started to cry," she said. "It was the most incredible moment. I cried again remembering that I had just summited all 14 8,000m peaks and made history."

Ms Brownlee and her team are now safely off the mountain and in Tibet recovering from the climb.

In May 2021, at the age of 20, she completed her dream of summitting Mount Everest. Over the next three years, she continued to take on the remaining world peaks over 8,000m (26,246ft).

Ms Brownlee has also become the youngest female in the world to summit K2 and the youngest person to summit Gasherbrum 1 without supplementary oxygen.

She told Sky News: "It was absolutely incredible. This has been my dream since I was eight years old."

Speaking about her last challenge - reaching the top of Shishapangma without supplementary oxygen - she said "it was very difficult... every step was gruelling... I wanted to throw-up the whole way".

There are only 14 mountains in the world which are over 8,000m above sea level and all are located in the Himalayan and Karakoram mountain ranges across Nepal, Tibet and Pakistan.

They include Everest (8,849m), K2 (8,611m), Dhaulagiri (8,167m) and Nanga Parbat (8,126m).

They are known as the "eight-thousanders" and provide a challenge for mountaineers.

There is no official document for who has completed all 14 summits, but most online records suggest it is limited to a few dozen people.

Climbing them can be incredibly dangerous, with many attempts of each peak having resulted in fatalities.

Read more from Sky News:
Inquiry warns of lax regulation in funeral sector
Met Office issues heavy rain warning
Ex-Chelsea boss primed to become England manager

Ms Brownlee says her father Tony was the inspiration for her to get into mountaineering. When she was eight, they completed the three peaks challenge (climbing Snowden, Scafell Pike and Ben Nevis in the UK) in just 22 hours.

She also told Sky News what motivates her to climb the highest - and most dangerous - peaks in the world.

"Climbing a mountain for me personally... it's freedom... it allows me to connect with myself... connect with nature, and allows me to push myself to the absolute limits," she said.

She explained that she plans to "stay in the mountains" by helping others complete high-altitude mountaineering and trekking trips.