In Britain at least 30 million people sat round their televisions to watch the spectacle; in America, despite the time difference that meant the live broadcast began at 5.00 am, some 23 million people watched. What is the interest in Britain's royal family? And why are people around the world still fascinated by monarchy, an ancient form of government which nowadays seems to have little power or relevance?
First, it must be said that the 29 April wedding was an impressive spectacle, a showcase of pageantry that was colourful, traditional and solemn. Britain has always been good at adapting ancient ceremonies to modern times, and this wedding seemed almost made for television and the internet age, with millions of tweets around the world. The famous personalities present in Westminster Abbey - David Beckham and Elton John among many other - created global interest in an age given to gossip and celebrities. There was huge excitement about the bride, who looked graceful and behaved with assurance, and her dress, which had been almost a state secret. And there was the moving contrast between a young prince and his girlfriend from university days, and the Queen, now 85, who has been on the throne for almost 60 years, the third longest reign in British history.
The second factor is what the wedding said about Britain and about the British royal family. The Queen remains consistently popular, but in the past 30 years, since the wedding of her son Charles to Princess Diana, the royal family has suffered scandal, tragedy and a huge blow to its reputation. The low point came in 1997 with the death in a car crash of Diana, after her divorce from Prince Charles, when the monarchy was widely despised.
Bit by bit, however, the monarchy has been able to rebuild its image. The Queen has benefited from the perception that she represents stability, continuity and national unity at a time of social change and economic challenge. Her carefully balanced political neutrality means that she has kept the institution of monarchy above party politics. She is thus able to represent Britain, now a multi-ethnic country of many cultures and religions, as a head of state who can make the symbolic gestures necessary to project national values and identity. Indeed, only three weeks after the wedding, she began one of the most important visits of her long reign, making a state visit to the Republic of Ireland. Because of the long and bitter conflict with the country that once formed part of the United Kingdom, no British monarch has set foot in southern Ireland for 100 years. Only a monarch is able to set the seal on reconciliation between two divided peoples.
Several West European nations are also monarchies; like Britain, their kings and queens play no political role, but represent Norway, Sweden, Denmark, Belgium, the Netherlands and Luxembourg on the international stage. In Spain, the monarchy plays a more obvious political role as guarantor of democracy. It was restored after the end of the Franco dictatorship, and King Juan Carlos is seen as a symbol of the new Spain.
The disadvantage of monarchies is not simply that they are inherently undemocratic, being based on the accident of birth; they are also subject to gossip, scandal and speculation that undermines respect. Most have survived, however; even Prince Albert has retained his throne in tiny Monaco. But although some former communist countries that abolished monarchies have accepted back their kings as visitors, none is thinking of restoring the institution. The nearest a former monarch came to reclaiming his throne was in Bulgaria, when former King Simeon II, deposed in 1946 at the age of 9, returned from exile to become Prime Minister in 2001. He got some of his lands back; but his political career did not last long. He and former King Michael of Romania, now 89, are the last surviving heads of state since the Second World War. Prince Alexander of Yugoslavia returned from exile in Britain to live in Serbia, but has not been given his throne back. King Constantine, deposed from the Greek throne after the 1967 military coup, remains in exile in London and has refused to abdicate.
Beyond Europe, monarchies still have political power, especially in the Arab world. The kings of Jordan, Morocco and Saudi Arabia, like the Emir of Kuwait and Sultan of Oman, are still absolute rulers, able to appoint and dismiss prime ministers and not subject to control by parliament. Most have successfully avoided the turmoil that has shaken other Arab countries. But the King of Bahrain, a Sunni, is deeply unpopular with the Shia majority, and his battle to remain in power has led to violence.
Few monarchies remain elsewhere. In Thailand, the ailing king Bhumibol has been on the throne for 64 years and is a figure of stability among the many coups. But though deeply revered, his influence is waning: it is unclear whether his son will enjoy the same respect. Meanwhile, the Emperor of Japan is widely respected, but the monarchy is struggling to adapt to a less formal and more open age in Japan.
No republic – an inherently more democratic form of government – is considering reverting to a monarchy associated with absolute power. But many ardent republicans, especially in America, still hanker for the glamour and tradition of royalty. Prince William and his new bride can be assured of global attention for the rest of their lives.