The Golden Lion Throne was the name given to the seat of power for House Corrino, since the symbol of that great House was the golden lion.
During the days of the Old Imperium, the name was also synonymous with the Imperial throne, since House Corrino had been the rulers of the Old Imperium for thousands of years. Many Great Houses aspired to place one of their own on the Golden Lion Throne.
The Golden Lion Throne itself was said to have been carved out of a single piece of Hagal quartz.
The term held some meaning during the rule of Paul Atreides. But by the later years of the God-Emperor Leto II, and the subsequent disruption of the Famine Times, the Golden Lion Throne ceased to be either a tangible entity or meaningful concept.