Marcus Agius is to step down as chairman of Barclays in the wake of the rate-rigging scandal.
Mr Agius, who was chairman for six years, said: "This has been a period of unprecedented stress and turmoil for the banking industry in particular and for the wider world economy in general."
The move comes after Barclays was fined £290 million by UK and US regulators for manipulating the Libor, the rate at which banks lend to each other.
The bank said Mr Agius will remain in post until an "orderly succession is assured" and added Barclays non-executive director Sir Michael Rake has been appointed deputy chairman.
Mr Agius added: "I am truly sorry that our customers, clients, employees and shareholders have been let down. Barclays is full of hard-working, talented individuals whose integrity is not in question."