Boyan Petrov (, born 7 February 1973 – disappeared 5 May 2018) was a Bulgarian zoologist and mountaineer, who worked at the National Museum of Natural History in Sofia.Boyal Petrov, NMNHS

At the time of his disappearance he had climbed 10 of the 14 eight-thousanders, all without supplemental oxygen and no help from Sherpas. He was the first Bulgarian to climb four of those mountains: Gasherbrum I (2009), Kangchenjunga (2014), K2 (2014) and Manaslu (2015). He climbed them despite insulin-dependent diabetes, proving that physical activity does not interfere, but helps to control diabetes. As of 2024, Boyan Petrov and Atanas Skatov are the Bulgarian climbers with the highest number of successful ascents of 8000 meter peaks but Skatov was climbing with commercial expeditions and almost always with supplemental oxygen.

Achievements On 20 May 2014 he became the first Bulgarian to climb the third highest peak on Earth Kangchenjunga (8586m), as well as the first diabetic to ascend to such an altitude and without oxygen.Тайнствен глас водил Боян Петров към върха , МониторBulgarian Mountaineer Boyan Petrov Climbs Kangchenjunga Summit On 23 July he climbed Broad Peak (8047m).Boyan Petrov: The most successful summer of Bulgarian mountaineering, Bulgarian National Radio On 31 July 2014 he became the first Bulgarian to climb the second highest peak on the planet K2 (8611m), which also made him the 35th person to climb three eight-thousanders in less than 100 days.Боян Петров: Най-добрият алпинист е живият алпинист OFFNews His double climb – on Broad Peak and K2 – in 8 days, was also a world record. For these remarkable successes the Bulgarian climber was greeted with a video message by mountaineering legend Reinhold Messner. His documentary film about his climbs "3x8000" was broadcast on Bulgarian National Television in December 2014.БНТ излъчва втора част на филма „3x8000“БНТ излъчва филм за алпиниста Боян Петров He reached the summit of Mt. Dhaulagiri (8167m) on 29 September 2017 at 01:00 pm without the help of supplementary oxygen.

Boyan Petrov was a cancer survivor and a diabetic.Гергана Лабова, "Боян Петров: жив си, когато не се отказваш", www.gnezdoto.net, 2015, in Bulgarian. Retrieved 28-07-2016. In 2008 he fell while climbing in the Alps and broke his leg.Мара Калчева, "Боян Петров: Диабетик съм, но катеря осемхилядници!", www.blitz.bg, 28-05-2013, in Bulgarian. Retrieved 28-07-2016. During the descent of Gasherbrum II in 2009 he fell in a glacial crevasse and was saved by a group of Spanish climbers.Бойко Оков, "Покорителят на Гашербрум -1 и Гашербрум – 2 Боян Петров: Бях сам, спикел и щека на 30 метра от върха", www.verticalworld.net, 28-08-2009, in Bulgarian. Retrieved 28-07-2016. In 2013 Petrov suffered another leg fracture due to a car accident. Despite his injuries, in the following year he achieved a hat-trick by successfully climbing Kangchenjunga, Broad Peak, and K2 with internal fixators in this leg.Бойко Оков, "Властелинът на осемхилядниците покорил К2 с 12 пирона в крака", www.blitz.bg, 17-08-2014, in Bulgarian. Retrieved 28-07-2016. After the descent of K2, he suffered a serious hypoglycemic crisis while in base camp, lost consciousness and was able to recover with the help of Polish climbers.Michał Bugno, "Dziękują Polakom za uratowanie człowieka na Broad Peak. "To bohaterstwo!", sport.wp.pl, 12-09-2014, in Polish. Retrieved 28-07-2016.Стефан Чолаков, "Боян Петров: Под К-2 имах криза заради кръвната захар" , "24 часа", 14-08-2014, in Bulgarian. Retrieved 28-07-2016.

Disappearance Petrov was declared missing while climbing Shishapangma. On 5 May 2018 his tent and sleeping bag were found in the area of Camp-3 of the mountain, which is around 7,300 metres altitude. Due to Bulgarian diplomatic efforts, for the first time in 20 years, a Nepalese rescue helicopter was allowed to fly above China. No other signs of him were found either around Camp-3 or on the Shishapangma. The search for him was discontinued on 16 May."The final report puts to rest all speculations surrounding the Boyan Petrov Search Operation", "Dream Wanderlust", 17.05.2018. According to other climbers, he may have fallen into a crevasse on the way to the top.

Ascents of peaks over 6000 meters + Year Peak Height Mountain State Notes 2001 Broad Peak 8047 m Karakoram Altitude reached 7300 m 2003 Lenin Peak 7134 m Pamir 2004 Aconcagua 6962 m Andes 2004 Denali 6195 m American Cordillera 2005 K2 8611 m Karakoram Altitude reached 8200 m 2007 Khan Tengri 6995 m Tian Shan 2009 Gasherbrum I 8080 m Karakoram First Bulgarian ascent. Without oxygen 2009 Gasherbrum II 8035 m Karakoram Altitude reached 8030 m 2010 Peak Korzhenevskaya 7105 m Pamir 2010 Ismoil Somoni Peak 7495 m Pamir 2014 Kangchenjunga 8586 m Himalayas First Bulgarian ascent. Without oxygen 2014 Broad Peak 8047 m Karakoram Without oxygen 2014 K2 8611 m Karakoram First Bulgarian ascent. Without oxygen 2015 Manaslu 8163 m Himalayas First Bulgarian ascent. Without oxygen 2016 Annapurna I 8091 m Himalayas Without oxygen 2016 Makalu 8485 m Himalayas Without oxygen 2016 Nanga Parbat 8126 m Himalayas Without oxygen 2017 Gasherbrum II 8035 m Karakoram Without oxygen 2017 Dhaulagiri 8167 m Himalayas Without oxygen 2018 Shishapangma 8027 m Himalayas Reached Camp 3 at 7,500 m before disappearing

Source:CV of Boyan Petrov, National Museum of Natural History, Sofia, Official Site. Retrieved 24-05-2016.

See also Hristo Prodanov List of deaths on eight-thousanders List of people who disappeared mysteriously: post-1970

References