Nyai Loro Kidul or Nyi Roro Kidul or Ratu Laut Selatan ("Queen of the South") and also known as Kangjeng Ratu Kidul is thought to be a Javanese goddess. The identity is of a goddess or Queen of Southern Sea of Java (Indian Ocean or Samudra Kidul) in Javanese and Sundanese mythology.
Nyai Loro Kidul has many different names, which reflect the diverse stories of her origin. However, for many Javanese it is important that various honorifics, such as Nyai, Kangjeng, and Gusti, are used when mentioning her name. People who invoke her also call her Eyang (grandmother).
Nyai Loro Kidul controls the violent waves of the Indian Ocean. Her dwelling-place is in the heart of the Indian Ocean, which is told to be her realm. Sometimes she is referred as one of the spiritual queens or wives of the Sultan of Yogyakarta or corresponding to Merapi-Kraton-South Sea axis in Yogyakarta Sultanate.
It was Panembahan Senopati (1586-1601 AD), founder of the second Mataram Kingdom, and his grandson Sultan Agung (1613-1645 AD) who named the Kanjeng Ratu Kidul as their bride in the Babad Tanah Jawi.
Nyai Loro Kidul is often illustrated as a mermaid. In this image she is referred to Nyai Blorong who has a mermaid tail as well the lower part of the body of a snake. These creatures take your soul for any wish of material matters addressed to them.
One original telling is about Dewi Kadita of the Pajajaran Kingdom, West-Java, who desperately seeks for the south after black magic that had hit her. She jumps into the violent waves of the Indian Ocean where the spirits and demons crowned the girl to the legendary Spirit-queen of the South.
A very complicated story goes about the Ajar Cemara Tunggal/Adhar Tjemara Toenggal on the mountain of Kombang, a male seer who actually was the great-aunt of Joko Susuruh. She told him to go to the east of Java to found a kingdom on the place where a maja-tree just had one fruit; the fruit was bitter (pait) and the kingdom got the name of Majapait.
The seer Cemara Tunggal would marry the founder of Majapait and, any descendant in first line, to help in all kind of matters. Though after he (the seer) would have transmigrated into the "spirit-queen of the south" who shall reign over the spirits, demons and all dark creatures. After all it is because of these traditions that the myth about Nyai Loro Kidul got a Sundanese, West-Javanese origin.
Pelabuhan Ratu, a city in West Java, celebrates an annual holiday in her honor on (New years day in the Javanese calendar). The special day which is dedicated to the Nyai Loro Kidul is on April, the 6th. She is also associated with Parangtritis, Pangandaran, Karang Bolong, Ngliyep, Puger, Banyuwangi, all along the south coast of Java.
There is a local belief that wearing a green garment in these areas will anger her and will bring misfortune on the wearer, as green is her sacred colour. The Samudra Beach Hotel keeps room 308 furnished with green colours & reserved for Nyai Loro Kidul. The first president, President Soekarno, of Indonesia was involved with the exact location and the idea for the Samudra Beach Hotel. In front of the room 308 there is the Ketapang tree where Soekarno got his spiritual inspiration.
Legends recount her love for the Sultan Agung of Mataram, which continues to be recounted in the ritualized bedhaya dance by the royal line of Surakarta, and she is honored by the sultans of Yogyakarta. When Sri Sultan Hamengkubuwono IX died on October 3, 1988, the Tempo newsmagazine reported her sighting by palace servants, who were sure she was paying her final tribute to the dead ruler.