The Great Wizard is a central character in the myth of the founding of the Agatean Empire, on the Counterweight continent. In the legend, the Great Wizard harnessed lightning to create an army out of the soil to fight for One Sun Mirror. This army, known as the Red Army, enabled One Sun Mirror to unite the continent and create the Empire.
In more modern times, a revolution in the Agatean Empire was sparked by the book What I Did On My Holidays. These revolutionaries decided to bring the "Great Wizzard" mentioned in this book to the Empire to lead the revolution. This Great Wizzard was Rincewind, and the events of this revolution take place in Interesting Times.
"Rinso" falls on his arse and ends up discovering a multitude of statues buried in a field of mud outside the major city and - with a clever device-y type thing on the forearm (very like the control panel on the arm of the Predator) - brings all of the statues to life, drags them to the surface where they burst through the mud to win the day for the Silver Horde and allied revolutionaries. The support of the Great Wizard, as expressed by his Red Army, helps reinforce Cohen's claim to the throne of the Empire.
His most famous saying is "Goodbye"- something quite a lot of Agateans learn just before he vanishes in a cloud of dust...
The army that the Great Wizard statue is found with is more-than-slightly reminiscent of the Terracotta Army (traditional Chinese: 兵馬俑: literally "soldier and horse funerary statues") found near Beijing in 1974. The Terracotta Warriors and Horses is a collection of 8,099 larger than life Chinese terra cotta figures of warriors and horses located near the Mausoleum of the First Qin Emperor (秦始皇陵).
The control options for the golem army -- walking, digging, climbing -- are reminiscent of those in the video game Lemmings, in which hordes of identically-moving bushy-headed creatures must be guided through a subterranean obstacle course without them walking off cliffs, getting trapped in corners, etc. Several golems under Rincewind's control get bogged down or destroyed by mindlessly repeating the last command he sent them, much like many an unfortunate Lemming.