Veteran polar explorer Sir Ranulph Fiennes set sail for Antarctica on Thursday on board the SA Agulhas research vessel.
The ice-strengthened South African ship was moored alongside HMS Belfast in the Pool of London and Tower Bridge was raised for the vessel's departure.
Sir Ranulph and his five colleagues aim to complete 'The Coldest Journey' – the first-ever trans-Antarctic winter expedition.
The expedition was launched by the Prince of Wales who visited the SA Agulhas on Thursday to wish the team well.
The Coldest Journey will also attempt to raise $10 million for Seeing is Believing, a global charitable initiative to fight avoidable blindness.
During their sea voyage the team will undertake a number of scientific tasks to provide unique data on marine life, oceanography and meteorology.
On 21 March 2013, the equinox, the six expedition members will begin a six month journey to reach the Ross Sea. Their route from the Russian base of Novolazareskaya ('Novo') to Captain Scott's base at McMurdo Sound – via the South Pole – will test the limits of human endurance.
During this six month period the expedition team will travel nearly 4,000 kilometres, mostly in complete darkness in temperatures as low as -90°C.
The expedition team will have to be entirely self-sufficient and there will be no search and rescue facility available, as aircraft cannot penetrate inland during winter, due to darkness and risk of fuel freezing.
"This will be my greatest challenge to date," said Sir Ranulph.
"We will stretch the limits of human endurance. Britain and the Commonwealth has a strong heritage of exploration, from Captain Cook 300 years ago to the present day.
"As such, it is fitting that a Commonwealth team should be the first to fulfil this last great polar expedition.
"It is a unique opportunity to carry out a number of scientific tasks in the extreme polar environment, which will make a significant contribution to our understanding of the true effects of global warming on the Antarctic continent."