Conceived by Henry Cole, enthusiastic after his visit to the Paris Exposition in 1849, the London Great Exhibition was the first truly international Expo, where the most advanced themes and innovations of an entire era converged from a global-scale context. No subject was given, the vocation was purely commercial, and above all, to mark the distance from previous exhibitions, came the unprecedentedly strong identification between an event and an iconic architecture: the Crystal Palace. The 39-meter-high iron-and-glass greenhouse designed by Joseph Paxton housed on its 92.000 square meter surface a powerful scenic system, created through the interaction of Owen Jones's decorations (from which Jones himself drew his 1856 book The Grammar of Ornament) with the over 100.000 objects on display, ranging from the first public toilet to the legendary Koh-I-Noor diamond. After the three-month exhibition — which reportedly attracted 6 million visitors — Prince Albert wanted to continue the educational spirit of the project by establishing the Museum of Manufacturers, the future Victoria and Albert, in 1852.

©Photo Josse/Scala, Forence, 2017. In Domus 1014, June 2017

The exhibition celebrating 100 years since the storming of the Bastille was based on the spectacularisation of progress (panoramic hot-air balloons, reconstructed villages, magnificent shows), as well as of a mainly colonial history. However, this Expo was one of the first to also assert itself as an urban-scale display. The whole of the Champ de Mars was in fact occupied by a multitude of multifariously shaped and themed buildings, created under the supervision of Charles Garnier (the architect of the Opéra), linked by the innovativation of an electrical network, and by a temporary railway line. Clearly the symbol that the event would leave to history is the 325-metre trellis, made of over 18.000 metal elements, known as the Eiffel Tower; but the celebration of the iron industry will also see the engineer Gustave Eiffel involved in working with Ferdinand Dutert and Victor Contamin in designing the great Galerie des Machines, a 115-metre span roof, later dismantled in 1909, that throughout a twenty-year career would prove extremely versatile, hosting the most diverse themes.

The first half of the 20th century would pass amidst forced interruptions and increasingly sharp contrasts between the rhetoric of the exhibitions and actual international tensions. After war and reconstruction, Expo 67 represented a return to the large scale and the spirit of innovation of the fundamental Universal Expositions, applied above all to the realms of the city, of construction and housing. The theme was Terre des Hommes/Man and his world. Man and his activities. Everything spoke about future and research, the whole site was covered with futuristic multi-screen projections, but the urban legacy of the event was the aspect that would make history: the site itself was largely created from scratch, extending an island in the middle of the Saint Laurent river and adding a new one not too far. Then there were the buildings: Frei Otto's enormous tensile structure for Germany, Habitat 67 housing cluster designed by Moshe Safdie as an aggregation of prefabricated volumes, and the icon of an entire era, the Biosphere, the 60-meter-high geodesic dome designed by Richard Buckminster Fuller for the United States pavilion, originally wrapped inside an acrylic membrane (burnt down in a fire in 1976) and operating today as the permanent structure of an environment museum.

The turning of the millennium produced a change of pace: World Expos became five-yearly, and the strategic choice of their location became a priority, so that the legacy of the great event could be better reabsorbed by host cities, avoiding abandonment as it happened in Seville (1992) or Lisbon (1998). The masterplan was ready in 1994, providing a basis to the development of a large number of soon-to-be-famous architectures, first and foremost the Dutch pavilion by MVRDV, but also the Japanese gridshell designed by Shigeru Ban; and that was what saved the event from complete disaster (ineffective communication of the theme, less than half of the expected visitors; critics at the time wondered about the end of an era, if not of the Expo model itself). Many structures have been in fact reabsorbed into the urban fabric: the Mexican pavilion by Ricardo Legorreta, for example, has become the library of the Braunschweig University of Arts, and the Dutch pavilion, after ending up for sale on eBay, is now about to be transformed into a co-working structure. A very Expo note: for the occasion, Kraftwerk created the Expo2000 jingle, which was later extended into a song.

It is impossible not to talk about cities when talking about Expo 2010. The theme of the first major Expo of the millennium — the first to take place out of the extended “Western bloc” – was Better City, Better Life. The monumental event, recognized as the most expensive edition to date, landed on a large area joining the two banks of the Huangpu River, causing expropriations and the relocation of thousands of residents — as it was immediately denounced — and for six months hosted the largest number of countries ever assembled, ironically, around themes of improving the living conditions of urban populations. The architecture did not spare large numbers and large scale, as stated by the monumental Chinese pavilion, as well as it consecrated a new generation of star-architects  such as Thomas Heatherwick, the author of the British Pavilion. The legacy of the event today is represented by the Expo Park, where the Chinese pavilion has been preserved and a museum of the history of the Expos has been created.

photo: Cesarexpo, cc by-sa 3.0