By Caroline Wyatt
Defence correspondent, BBC News
Gen Richards has said Afghanistan's people "entered his bloodstream"
Gen Sir Richard Dannatt has handed over his post as professional head of the British army, or Chief of the General Staff, to Gen Sir David Richards.
His appointment comes at one of the most testing times for the west's mission in Afghanistan, amid increasing public scepticism over whether the sacrifices being made in Helmand are worth it.
Providing the necessary military leadership will be no easy task, while the new chief of the general staff faces leadership challenges on many other fronts, too.
He will not only be fighting a growing insurgency in southern Afghanistan, but also battling for resources for the Army back in Whitehall, at a time of increasing financial strain and competition amid all three services for future spending.
The man he has taken over from, Gen Sir Richard Dannatt, often found himself at odds with ministers, and was seen by some as too outspoken on issues ranging from soldiers' pay and accommodation to the number of British helicopters in Helmand.
Gen Dannatt, who retires after 40 years in the Army, is due to take up the post of chairman of the Royal United Services Institute think-tank, as well as becoming constable of the Tower of London.
Gen Richards is seen as a good communicator who is also politically astute, and perhaps more likely to fight his battles behind closed doors.
GENERAL SIR DAVID RICHARDS
Commissioned into Royal Artillery 1971
Nine years in the Far East, Germany and the UK
Four tours in Northern Ireland
Became Assistant Chief of the General Staff in 2002
Commander of the International Stabilisation and Assistance Force Afghanistan between May 2006 and February 2007
Operational awards include a Mention in Despatches, CBE, the DSO and KCB
He has extensive operational experience in East Timor, Sierra Leone, and - crucially - first-hand knowledge of the challenges in Afghanistan gained as commander of Nato coalition forces there between 2006 and 2007, another key period in the battle against the insurgency.
Gen Richards, 57, has called himself "a seat-of-the-pants soldier", and has said that during his time in Afghanistan, the people and the country "entered my bloodstream".
His tour of duty there earned him an operational KCB - a knighthood - while his mission in Sierra Leone in 2000 - during which he persuaded Tony Blair and Robin Cook to allow him to return and run a bigger intervention to finish off the job successfully - saw him awarded a DSO for his leadership and 'moral courage', as well as a CBE for the operation he commanded in East Timor in 1999.
As well as trying to ensure the right resources for Britain's part in the multi-national effort in Afghanistan, Gen Richards must also focus on consultations in Whitehall ahead of the forthcoming strategic defence review.
The review will bring to a head difficult decisions that must be faced by all three services on equipment, capabilities and priorities for the UK's Armed Forces.
However, the long-running campaign that the new professional head of the British Army inherits in Afghanistan is likely to provide some of the greatest of his immediate challenges.