London touted its ethnic mix as a positive when bidding for the 2012 Games. Then-Prime Minister Tony Blair promised the International Olympic Committee in 2004 that the city's "amazing diversity" would contribute to an Olympic atmosphere "like no other."
But, often, from when native warrior queen Boudica torched the Romans' London until today, the pieces in this human jigsaw haven't slotted easily together.
British empire-builders practically invented racism, pushing derogatory and offensive notions of supposed African inferiority to try to justify the slave trade.
Fascist leader Oswald Mosley and his black shirts rallied against Jews in the 1930s in Hackney, another Olympic host borough in London's East End.
Under the headline, "Noisy Parties 'A Threat to Race Peace,'" Newham's local paper, the Recorder, reported in 1969 that loud music and dancing nights were "causing bad feeling between West Indians and their neighbors," identified as white.
"West Indians must give up some of the things they used to do," it quoted a community relations officer, Alexander Kirby, as saying, "because they don't fit into their new environment."
Clive Bettington, chairman of the Jewish East End Celebration Society, says he has been stoned and spat on by Muslim youths while leading walking tours of Jewish landmarks.
Altab Ali Park in the East End's Tower Hamlets, another Olympic host borough, is named after a Bengali clothing worker murdered on his way home in 1978 in a racist attack by three teenagers.
And in London's May 3 election for mayor, the far-right, anti-immigration British National Party fielded a candidate who is himself an immigrant. Carlos Cortiglia, born in Uruguay to parents of Italian and Spanish ancestry, campaigned that London's "multiculturalism has clearly led to division and confrontation instead of integration."
Go figure. Perhaps only London could produce such a walking contradiction.
Here, on city buses, you'll hear people speaking languages you might recognize and certainly many you do not.
In practical terms, competing in this global shop-window will mean that if Usain Bolt hungers for home cooking this July he can nip quickly to Caribbean Scene on the Olympic Park's fringe for curry goat, saltfish and a side of plantain. The Olympic 100- and 200-meter champion can't miss it: the restaurant has the Jamaican's portrait painted on an inside wall.
For Ethiopian vegan curries, 5,000 and 10,000 champion Kenenisa Bekele should try the East End's Brick Lane market. The stall holder there who spoons out the stews is from Myanmar. That might be bizarre, unthinkable even, in a less cosmopolitan city, but it neatly captures London's mishmash.
Muslim athletes could say prayers at the Great Mosque on Brick Lane's junction with Fournier Street. Built as a chapel for French Protestant Huguenots in the 1700s and later converted into a synagogue and then a mosque, it could be a metaphor for modern London's overlapping cultures and immigrant histories.
So, too, could the Shanghai restaurant in Dalston west of the Olympic Park in an eatery which used to sell eel pie and mash potatoes, the most traditional East London fare.
In the delightfully preserved 150-year-old decor, between serving a nurse from Cuba who ordered butterfly prawns and sweet roast pork and a white woman who wanted noodles for her two children, manager Peter Cheung dug out a photo of one of his most regular patrons to show off to a recent visitor.
Cheung moved to London from Hong Kong. The photo was of British TV broadcaster and commentator Hardeep Singh Kohli. He is a British Indian Sikh who grew up in Glasgow, Scotland.
Londoners, a worldly breed, indeed.
John Leicester is an international sports columnist for The Associated Press. Write to him at jleicester(at)ap.org or follow him at http://twitter.com/johnleicester