From A Wiki of Ice and Fire
The Summer Islands or Summer Isles are a large archipelago located to the south of Westeros and Essos, and west of Sothoryos. The islands separate the Sunset Sea to the west from the Summer Sea to the east. The northern-most islands of the group have been mapped, but it is not known how far south the island chain extends. The mapped portion of the chain includes three large islands and numerous smaller ones.
The three largest islands, from north to south, are Walano, Omboru and Jhala. The Smiling Sea divides Walano and Omboru, and the Indigo Straits divide Omboru from Jhala. Walano contains the capital of the Summer Islands, Lotus Port, as well as the towns of Last Lament and Tall Trees Town. Jhala contains the settled valleys of Red Flower Vale and Sweet Lotus Vale, including the city of Ebonhead. The numerous smaller islands include Koj and the Isle of Birds, among others.
The natives of the islands are an ebony-skinned people who speak their own language and often wear capes of brightly colored feathers. The act of lovemaking is considered an important and even holy skill. Prostitution is a respectable profession, practiced even by the high-born islanders. Summer Islanders respect their elderly, and mourning customs include celebrating the dead with wine and lovemaking. Archery is another important cultural skill, their special bows have a longer range than most others, giving their merchant boats added defense against pirates.
The history of the Summer Islands is not known in detail. However, some years after Robert's Rebellion there was a civil war on Jhala which saw Prince Jalabhar Xho of the Red Flower Vale desposed. He sought refuge in King's Landing and spent many years petitioning King Robert Baratheon for military assistance in retaking his homeland. Robert was attracted by the idea of invading the Summer Islands, but his advisors convinced him it was a foolhardy venture. Despite this negative response Xho remains in exile in King's Landing.
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