Olmec colossal heads by Matthew Stirling in 1938 spurred the first archaeological investigations of Olmec culture. Seventeen confirmed examples are known from four sites within the Olmec heartland on the Gulf Coast of Mexico. Most colossal heads were sculpted from spherical boulders but two from San Lorenzo Tenochtitlán were re-carved from massive stone thrones. An additional monument, at Takalik Abaj in Guatemala, is a throne that may have been carved from a colossal head. This is the only known example from outside the Olmec heartland. Dating the monuments remains difficult because of the movement of many from their original contexts prior to archaeological
The Olmec-Maya and Now else in his art was "ancillary" to "the burning urge" to express these parallels. "The Olmec-Maya and Now" was first exhibited at the Commonwealth Institute in London in June 1985. In 1989, the artist Denis Bowen remembered it as "a major exhibition with a significant body of work of the highest calibre" which "assure[d] [Williams'] place in the British art scene". The exhibition was opened by Terry Waite. One of the paintings in the series, "Olmec Maya—Now and Coming Time", was presented to the Tate by the Aubrey Williams Estate in 1993. The Olmec-Maya and Now "The Olmec-Maya and Now"