The Golden Age of the Gnomes was a time of immense prosperity for the gnomeish race. The Golden Age's exact duration of time remains a point of debate, although it is usually considered to have begun in roughly 1950 of the Fourth Age and lasted until King Healthorg's death in the early Fifth Age.
The Golden Age of the Gnomes began with the success of the Gnomish Empire in the Thorobshuun - Gnome War. The gnome's victory at the Battle of Atarisundri ensured that the Thorobshuun would not return, and with few enemies and many allies: amongst them the elves of Tirannwn and the human tribes that would eventually form Kandarin.
With this security and newfound freedom the Gnomish Empire prospered economically, politically, militarily, and culturally. The Tree Gnome Stronghold became amongst the greatest cities in Gielinor and King Healthorg was renowned as amongst the greatest of monarchs.
As Healthorg grew old, though, he became increasingly ineffective as leader, even with the help of his close companion Hazelmere the Ethereal. Scholars attribute this decline to many other reasons as well. The silent Arposandran War was already beginning to eat away at the base of the Empire, while the Khazard - Gnome War was beginning to take hold to the south. The Elven Civil War had left the elves in great conflict while the Dreaded Years of Tragedy had made religious tension in the region greater than ever.