 The Reach is the most lush and fertile region of Westeros, ruled by House Tyrell from Highgarden.The Tyrells were stewards to House Gardener, the Kings of the Reach before Aegon's conquest.After the last Gardener King was killed on the Field of Fire, the Tyrells surrendered Highgarden to Aegon and were rewarded with both the castle and the position of overlords of the Reach.