Garth Gardener was a legendary King of the First Men in the Age of Heroes. He was the founder of House Gardener and the first King of the Reach. According to legend, Garth Greenhand wore a crown of vines and flowers and was said to make the land bloom.
King Garth's line ruled the Reach until the Targaryen conquest, becoming extinct with the death of Mern IX, the last King of the Reach. Nevertheless, several of the noble houses of the Reach, such as House Tyrell and House Florent, claim their descent to Garth Greenhand.
In the books
Half of the great noble Houses from the Reach claim descent from Garth Greenhand and House Gardener, of which House Tyrell and House Florent are the most prominent. Other powerful noble Houses in the Reach descended from Garth are House Rowan and House Oakheart. Because House Tyrell never ruled as kings, and because they are only one of several Houses that claim descent from Garth (and not even as close a descent as the Florents possess), they have always felt somewhat uneasy in their claim to dominion over the Reach.
A large number of Garth's successors were named after him. There were ultimately at least twelve kings of the Reach named Garth, including the original, as there is mention of a coin minted during the reign of "Garth XII".
Garth Greenhand · Florian & Jonquil · The Grey King · The Griffin King · Joramun · Lann the Clever
The Night's King & the Night's Queen · The Rat Cook · The Prince That Was Promised