Gordon Brown has earnt more than £1.4m outside Parliament since he ceased to be Prime Minister, including his fees, travel and accommodation paid for by others and gifts.
An updated entry in the House of Commons register of members' interests shows that, like his predecessor Tony Blair, Gordon Brown has found a lucrative new career on the international lecture circuit.
But though his earnings are huge by most people's standards, they are dwarfed by the £12m-a-year income that Tony Blair generates, and they put Mr Brown outside the world's top 10 highest-paid after-dinner speakers.
Mr Brown recently declared a payment of almost £63,000 for a speech to an investment company in China, Halter Financial.
The most lucrative speech that Mr Brown has delivered was made late last year, when he was paid almost £75,000 to address a conference organised by the "ANAP Foundation", a charity promoting good governance, and the Nigerian national newspaper ThisDay. The organisers also paid more than £20,000 to fly Mr Brown and his staff to Lagos and put them up.
In 2009, Tony Blair made around £390,000 for two half-hour speeches delivered in the Philippines.
Mr Brown has also appeared several times on the US lecture circuit, earning around £36,000 per speech. His role as Distinguished Global Leader in Residence at New York University has earned him more than £180,000 in fees and expenses.
He was paid more than £62,000 for one speech by a South Korean business newspaper, more than £61,000 for a speech to a bankin Moscow, and nearly £50,000 for a speech to the King Saud University in Riyadh.
His entry also records a three-day visit to China last June, paid for by the Chinese People's Institute for Foreign Affairs, a visit to Africa paid for by Kenya Airways, and a trip to Singapore in September paid for a company called Temasek Holdings. That was his second visit to Singapore in 2011. On the previous occasion, Visa International paid him more than £48,000, plus nearly £17,000 costs, to deliver a speech.
He received an advance of over £78,000 for his book, Beyond the Crash, published in December 2010. The Guardian also paid £7,000 for the serial rights, but all proceeds from the book have been pledged to the charity PiggyBankKids. Mr Brown has since been paid £22,500 as an advance for a book due to come out later this year.
Since he left Downing Street, Mr Brown has drawn some criticism for the low level of his parliamentary activities. He made two speeches in the Commons during 2011, and tabled 16 parliamentary questions.
So far this year, he has tabled seven parliamentary questions, all on a site in his constituency, Dalgety Bay in Fife, which has been contaminated by radioactive waste.
According to the register, Mr Brown has not personally pocketed any of the money he has earned from this extra-parliamentary work.
More than £127,000 has been given to charities, while nearly £997,000 in fees and just over £293,000 in expenses that he has generated have been paid to the Office of Gordon and Sarah Brown, which they set up to facilitate their campaigning and charitable work.
Gordon's Empire: Keeping up with the Blairs
Gross income: £1m (2010-11, excluding his MP's salary)
Number of organisations: One - the Office of Gordon and Sarah Brown
Number of staff employed: Unknown – but he has at least one
Book advance: £78,000 for 'Beyond The Crash'
Gross turnover: £12m (2011)
Number of organisations: Five - the Office of Tony Blair, Tony Blair Faith Foundation, Tony Blair Sports Foundation, Tony Blair Africa Governance Initiative, Office of the Quartet Representative
Number of staff employed: 120
Book advance: £4m (donated to charity) for 'A Journey'