Moore gave different accounts of the inspiration for the sculpture: it may reflect his observations of two pebbles that unexpectedly interlocked, or of a sawn bone fragment with a joint.

A working model (LH 514) was created in plaster in 1962 (now held by the Art Gallery of Ontario) and then cast in bronze in 1962 in an edition of nine.

The plaster model was finished in January 1964, and then sent to the Hermann Noack foundry in Berlin to be used to make the sand mould for a version cast in bronze.

Three bronze casts were originally made, including one artist's model, and a fourth was created much later in 1987, measuring 293.5 by 208 by 260 centimetres (115.6 in × 81.9 in × 102.4 in), and weighing about 1,800 kilograms (4,000 lb).

The first full-size bronze cast was exhibited at Documenta 3 in Kassel in 1964, and then installed outside the building of the Banque Lambert at Marnixlaan in Brussels.

It was blown off its base by a very strong gust of wind in 1990 and severely damaged: it was reinstated after repairs by the Noack foundry, but moved to a new taller cylindrical concrete plinth in 2004.