One of the ways Hadrian encouraged cultural integration was through architecture. He instigated temple-building projects across the empire, most notably in Athens and Jerusalem, and created structures in Rome that would serve as models and inspiration. Two of the greatest still stand - the Pantheon, which has the world's largest unsupported concrete roof; and the Castel Sant'Angelo, built as his mausoleum. The exhibition has various capitals, cornices and bricks bearing the stamps of their makers from his numerous projects. These, along with fragments of fresco and stucco decorations from his extraordinary villa at Tivoli, give a taste of the grandeur he encouraged.

Oddly, another means of unifying the empire came with the death of his Greek lover Antinous - a "shameless and scandalous boy", according to St Athanasius - who drowned in the Nile in mysterious circumstances in AD 130. Hadrian's grief was excessive: he founded a city where Antinous died and he encouraged a hero-cult to spring up across the realm and even as far as Georgia. More than 100 marble images of Antinous are known to exist, more than of anyone other than Augustus and Hadrian himself. The examples in this exhibition show a smooth-skinned boy of great beauty, modelled on classical gods; others portray him as a hunter (it was while hunting that Hadrian and Antinous met), as an athlete or as Dionysus or Osiris.

To demonstrate Hadrian's even-handedness there are also three portrait busts of his wife Sabina. They reveal a stately, clear-featured woman with a long, straight nose and small mouth. Tradition has it that theirs was a chilly union. He described her as "harsh" and "irritable"; she boasted that she avoided becoming pregnant by him because "offspring of his would harm the human race". This is probably another misconception; Hadrian in fact honoured her in statues and coins and granted her the title of Augusta.

Together, all these fragments - coins and marble, cups and masonry, sandals and rings - form a composite picture of Hadrian and the world he created. It makes for a striking likeness. Appropriately, the exhibition is taking place in the Round Reading Room of the old British Library, a building that is itself Hadrianic: it takes its shape and inspiration directly from the Pantheon in Rome.