A vast motorcade of gleaming limousines ferried the entourage of King Abdullah of Saudi Arabia to Buckingham Palace for the state banquet at the start of his official three-day tour.
Five jumbo jets kitted out to the height of luxury were used to airlift the King's entourage to Britain.
In addition to his 23-strong group of all-male personal advisers, which includes 13 members of the Saudi royal family, there were 30 officials ranging from cabinet ministers to economists and specialists in British affairs.
The King was also believed to have brought a handful of wives – he has been married more than 30 times – and 100 servants to attend to his personal needs. And as the octogenarian monarch has had heart problems, he was also thought to have in attendance what has been called a "travelling clinic".
Once safely disembarked, some of the world's richest princes were among 170 VIP guests at last night's glittering banquet at the end of the Mall.
They included the Interior minister, Prince Naif, responsible for law and order and personally concerned with the upkeep of Saudi Arabia's conservative Wahhabi tradition, and the Foreign minister, Prince Saud Al-Faisal, US-educated and supportive of reform, although anxious it should come from within the kingdom rather than being imposed by outsiders.
Also present were Crown Prince Sultan and his son, Prince Bandar. The crown prince runs the Ministry of Defence and Aviation, and has been heavily involved in negotiating Saudi Arabia's arms deals, not least the Al Yamamah deals with the UK and BAE systems, thought to have been worth $40bn (£20bn) over 20 years and which were subject to a Serious Fraud Office investigation suddenly dropped on the orders of the Attorney General, Lord Goldsmith, last year.
Prince Bandar, the National Security adviser and Saudi ambassador to Washington for 22 years, was also embroiled in the BAE inquiry. He was alleged to have received $1bn from BAE to sweeten the 1985 Al Yamamah deal. Prince Mohamed bin Nawaf, the Saudi ambassador to London, also attended the banquet.
In a rare concession to formal protocol, Gordon Brown paid £3,000 of taxpayer's money for white tie and tails for the event. He has refused to wear such an outfit for the Chancellor's Mansion House speech in London in June, insisting on a lounge suit instead. "The dress code for the event this evening is set by the Queen and the Prime Minister will abide by the dress code," said the Prime Minister's spokesman yesterday.
King Abdullah's complaint that British authorities ignored Saudi warnings of an imminent attack on the UK before the atrocities of 7 July 2005 might be more convincing if they came from the ruler of a country less sympathetic to the Islamist agenda.
From Margaret Thatcher onwards, prime ministers have been in no doubt about Saudi Arabia's crucial importance to the UK government. Over the years a policy of pragmatism has come to characterise all dealings between London and Riyadh.
This week, Gordon Brown and David Cameron will welcome the leader of one of the world's most vicious dictatorships to Britain. Both men will embrace King Abdullah al-Saud, who heads a regime in which, according to Amnesty International, "Fear and secrecy permeate every aspect of life. Every day the most fundamental human rights of people in Saudi Arabia are being violated."