Three Sage Kings
The Three Sage Kings were a trio of wise and cunning Kings of the Reach from House Gardener who peacefully dealt with the coming of the Andals to the Reach. The successive kings on the Oakenseat were Garth IX, his son Merle I, and Merle's son Gwayne V. Maester Yandel writes that "seldom had a conquest been achieved with less bloodshed".
The Gardeners, kings of First Men origin, were aware of the fighting in the Vale, the riverlands, and the stormlands as Andals advanced deeper into Westeros. Several Kings of the Reach strengthened their defenses and sought magical aid in preparation for the Andals. When Andals finally arrived in the Reach, however, the Three Sage Kings took a policy of accord and assimilation toward the newcomers instead of armed resistance.
Garth IX Gardener brought a septon to his court and made him one of his counselors. He also built the first sept at Highgarden, though he continued to worship the old gods. Merle I Gardener converted to the Faith of the Seven and helped fund the construction of septs, septries, and motherhouses throughout the Reach. Gwayne V Gardener was the first of his family to be born into the Faith and the first to be made a knight.
Merle and Gwayne wed Andal maidens to bind their fathers to the Gardener realm. All three kings took Andals into their service as household knights and retainers; Ser Alester Tyrell, the founder of House Tyrell, was made Gwayne V's champion and sworn shield, for instance.
In exchange for pledges of fealty, the Three Sage Kings bequeathed lands and lordships on the most powerful Andal kings who arrived in the Reach. Families formed by the intermarriage of First Men and Andal nobles include Houses Cuy, Graceford, Leygood, Orme, Roxton, Uffering, and Varner. As the centuries passed the noble houses of First Men and Andals intermarried so freely that it became impossible to tell them apart.
The Gardeners sought after Andal craftsmen, especially blacksmiths and stonemasons, and encouraged their bannermen to do the same. Thus the First Men of the Reach learned to arm and armor themselves in iron instead of bronze and strengthen their castles with Andal masonry.
Though some of the new-made Andal lords broke their vows in later years, most remained loyal. The leal Andals helped their Gardener kings and liege lords put down rebels and also defend the Reach from later generations of invading Andals.
When a wolf descends upon your flocks, all you gain by killing him is a short respite, for other wolves will come. If instead you feed the wolf and tame him and turn his pups into your guard dogs, they will protect the flock when the pack comes ravening.
They gave us seven gods, we gave them dirt and daughters, and our sons and grandsons shall be as brothers.