Varley explained that he had attempted to streamline the chain of command, setting up a group of managers covering all of Barclays different departments that answered directly to him.
"I could not and did not involve myself in the day-to-day running of the business heads' operations.
"At the peak of the financial crisis, my responsibilities included extensive political and regulatory engagement.
"The process whereby a public company engages in raises of capital, a process ultimately overseen by its board, requires intensive collaboration between experienced capital market professionals, working with internal and external lawyers, banks, brokers and other advisors.
"The Qataris had a reputation for being tough negotiators," explained Varley.
He told how the services agreement was: 'symbiotic with, but not dependent or conditional on, the Qatari capital raising.
"I did not regard the fee payment as connected to the capital raising, from a regulatory perspective the agreement was distinct and I received no contrary advice."
The jury heard how the bank's services agreement had been made primarily in return for Qatari assistance in accessing Middle Eastern oil and gas businesses.
At one point, the court heard, the Qataris became concerned and sought reassurance from then Prime Minister Gordon Brown that the government was not planning to intervene in the bank, fearing that their shares may be diluted as a result.
"I neither engaged in criminal conduct, nor did I sanction any criminal conduct," concluded Varley.
Glenn Leighton, who headed Barclays' financial institutions group and provided balance sheet advisories, said the Qatari capital raising and advisory service agreement fees were calculated together to form an "effective entry price."
He explained that such a calculation, where external factors would be 'baked in' to any calculations, was routine and did not imply that the services agreement was conditional on the Qatari's investing as part of the 2008 capital raising.
Mr Leighton explained that as part of the same calculation, other variables that might affect the price were also included, such the dollar to sterling exchange rate and the Libor rate.
The witness explained that Boath had tasked him with producing the model and they had conversations about how it should be calculated.
The jury were also read statements that were given by the defendants in interview during the Serious Fraud Office investigations.
Varley, of Notting Hill, Jenkins, of Malibu, California, Kalaris, of Knightsbridge, and Boath, of Henley-on-Thames, Oxfordshire, deny fraud by false representation, between May 1, 2008 and August 31, 2008.
Varley and Jenkins deny a second like charge of fraud by false representation, between September 1, 2008 and November 30, 2008.
The trial continues.
