This time London can put on an Olympics the city deserves.

As the only city to host the world's biggest sporting event three times, London's 2012 Olympics will be a full cream extravaganza compared to its reduced fat 1908 and 1948 Games.

London was called on at short notice in 1908 when original venue Rome pulled out after Mt Vesuvius erupted in Naples in 1906, diverting the Italians' finances and energy into rebuilding the city.

In 1948, three years after World War II and four years after the city was supposed to host the Olympics, war-ravaged London held what was known as the Austerity Games - no new venues, no villages, no extravagance.

Even though Britain is in the grip of its deepest recession and most severe austerity measures since then, seven years' preparation and a budget of STG9.3 billion ($NZ18.15 billion) ensure the 2012 Games have plenty of new venues, a sparkling athletes village and lots of extravagance.

While austerity is again playing a role, albeit indiscernible, in the Games, a different sort of war is a significant presence in 2012.

As the war on terror lingers, more than 40,000 soldiers, police and private security guards will be deployed in what British prime minister David Cameron describes as the "biggest and most integrated security operation in mainland Britain in our peacetime history".

Neighbours near the 1908 and 1948 Games venues were more likely to have had chimney sweeps on the roof rather than the rocket launchers authorities are considering installing on homes near Stratford's Olympic Park in London's east.

The rocket launchers scheme is part of a STG600 million ($NZ1.17 billion) security budget which was always going to remain immune from any austerity measures.

Even though Olympics minister Hugh Robertson last year admitted the Games were a "discretionary spend", the overall STG9.3 billion budget has also been left untouched.

Robertson says the Games will come in under budget and that 98 per cent of work was already complete on the state-of-the-art venues by March, four months before the opening ceremony.

The main stadium at Stratford was built before the austerity set in, but if organisers needed inspiration for cost cutting, they only needed to look to what happened on the other side of town in 1908.

The 2012 Games boast the fact the athletics, swimming and cycling will all be in Olympic Park, but that has nothing on the compact versatility of White City in 1908.

The White City stadium took 10 months to build at a cost of STG60,000, held 68,000 people and was a one-stop Olympic shop.

The swimming and diving pool was in the middle of the 536m athletics track which was circled by a 600m cycling track. And wrestling and gymnastics competitions were held on platforms in the infield, next to the pool and alongside tug-of-war and lacrosse.

But there wasn't too much of a crush at White City, with the Games running from April to October.

A century later, the 80,000-seat athletics stadium at Stratford took more than two years to build and cost STG530 million, the pool cost STG300 million and the futuristic velodrome STG90 million.

In 1948, there was no time and certainly no money to build anything new for the first Games since Berlin in 1936.

It was the make-do-with-what-we've-already-got Games. The already iconic Wembley Stadium was the main venue, while the Empire Pool next door was built for the 1934 Empire Games and the Herne Hill velodrome dated back to 1891.

Other events were held at existing venues scattered in and around London, just as they will this year at landmark sites including Lord's, Horse Guards Parade, Hyde Park, Greenwich, Wimbledon and Eton.

And athletes were billeted in schools, military camps and even suburban homes.

The Games were still in their infancy in 1908, it was the first time teams marched behind national flags and some bitter disputes resulted in a standardisation of rules and the introduction of judges from different countries, not just the host.

And the Olympic creed "the most important thing in the Olympic Games is not to win but to take part" was first delivered in London, 1908.

It was also the first and last time motorboating and real tennis were Olympic sports, while 60-year-old Swede Oscar Swahn won gold in running deer shooting and remains the oldest Olympic champion of all.

Rugby was another short-lived Olympic sport in 1908, with the final played, of course, at White City, on a field next to the pool.

A net couldn't stop balls landing in the drink, while mattresses were laid out along the pool edge to break the fall for wayward players.

Harry Kerr, competing for Australasia, won New Zealand's first Olympic medal claiming bronze in the 3500m walk but 40 years later they would return home empty-handed.

The 1948 Games also included some firsts. While WWII aggressors Germany and Japan were not invited, it was the first Olympics to include Communist countries and, accordingly, Czechoslovakian Marie Provaznikova became the first Olympic defector.

Dutch housewife Fanny Blankers-Koen was the star of the Games, winning four athletics gold medals at Wembley.

But the mother of three was one of only 355 women among the 4064 competitors, which was still a vast increase on the 44 women who competed alongside 1799 men 40 years earlier.

In 2012, women will make up around half of the expected 10,500 athletes from 204 countries competing in 30 sports.

It's a long way from 1908 when 22 countries competed in 22 sports and a significant advance on 1948 when 59 nations participated in 19 sports.

London itself has changed markedly in the 64 years since its last Olympics.

It's now a melting pot of cultural diversity, particularly in the east end home of the Games, where, in the host borough of Newham, only 45 per cent of adults speak English as their first language.

It's a truly world city and if anyone deserves to host three Olympics, London does.