A groundbreaking show on Delos mixes classical and contemporary art

EUCLID, THE father of geometry, ordained that the centre of a circle must be a fixed point. The Greek island of Delos, a thirsty patch of rock and thin soil that lies, roughly, at the midpoint of a ring of islands known as the Cyclades, violated this rule. The ancients imagined it to be drifting perpetually. It was said to have gained a fixed location only after serving as the birthplace of Apollo, god of wisdom and light, and probably also of Artemis, the moon goddess. Its reward for this hospitality was to be bound to the seabed by diamond chains. Previously known as Adilos (invisible, unmanifested), it was given the new name of Delos, which suggests something shown or demonstrated.

Stable co-ordinates were no guarantee of a stable life. In the realm of real history, this holy speck of land was contested by rival islands, city-states, empires and trading interests. At first there were benign competitions to build the finest temple; but in the Hellenistic and Roman eras Delos became an earthy duty-free market where slaves were the most visible commodity. More than 20,000 people lived on a dot 5km long by 1.5km wide; some had prosperous homes with superb mosaics. But there are also traces of a terrifying fire.