The Bulgarian expedition, which is set to complete a successful ascent of Everest without without oxygen sets, left late on Sunday.
The ten Bulgarian alpinists will try to climb up the peak from its northern, and most dangerous side. The expedition is dedicated to the 20th anniversary since the first Bulgarian climbing of the top.
Last week the ten members of the team met with Prime Minister Simeon Saxe-Coburg, who gave them the Bulgarian flag to unfurl it on Everest. They also met the country's President Georgi Parvanov who presented them with an icon to protect them.
A satellite connection will keep the alpinists in touch with Bulgaria all the time. They are expected to return to Bulgaria in June.