The Westerlands are one of the constituent regions of Westeros. They once formed an independent kingdom ruled by the King of the Rock before they were defeated on the Field of Fire by Aegon the Conqueror. King Loren Lannister bent the knee to Aegon and was permitted to remain ruler of the Westerlands.
Westermen are generally held to be reliable and steadfast, but they are fiercely loyal to the Lannisters over the Iron Throne. They have an avricious streak, possibly due to the immense riches to be found under the western hills and mountains, but field many strong and reliable knights. Thanks to the riches of the land, the Westerlands can field the best-equipped armies on the continent.
Bastards born in the Westerlands take the surname 'Hill'.
The Westerlands has many hills and mountains. The land borders the Reach, the Sunset Sea, and the Ironman's Bay.
The hills and the mountains of the Westerlands make the city very defensible. The main pass is guarded by the Golden Tooth castle. The Westerlands, on the other hand, are vulnerable to attack from the sea because the coastline is flat.
Three major cities in the Westerlands are Lannisport, Casterly Rock (House Lannister), and the Golden Tooth (House Lefford).
The Westerlands are not very fertile, but it is still a very rich region. There are several mines through the Westerlands, with gold and silver.
6000 years ago, the Andals invaded Westeros and created kingdoms. After that, the Targaryens invaded and won the war because of their dragons. After that, Tytos Lannister took over. No one dared oppose House Lannister in the Westerlands.
At the Battle of the Trident, the Westerland army sacked King's Landing. The main rebel, Robert Baratheon, was crowned and married to Cersei Lannister.