The area was originally known as Welikada and stretched from the Ethul Kotte bridge to the tram terminus at Borella. The Welikada Prison was originally within the village limits. The name Rajagiriya came from the former governor's residence, the grounds of which extended from Madinnagoda Road in the north to the Cotta road in the south. The house and grounds were later purchased by Ananda Coomaraswamy. According to historian Douglas Ranasinghe, a Malayali servant of Coomaraswamy's saw a large mongoose in the garden and shouted 'Raja kiriya' and the name stuck. There is another viewpoint about the origin of the name. Since Kotte kingdom was the main kingdom during 1412-1597, Rajagiriya area took a major place in Kingdom's security. In Sinhala Language, the word Rajagiriya is made of the combination of words 'Raja'+'Giriya'.'Raja' means 'King' and 'Giriya' means 'Neck' or 'Rock'. The castle was not that much far from Rajagiriya. Since there're no significant mountains or rocks and the area is almost a plain, it believes not to be meant with that Rock meaning. In the Sinhala language, neck is used to distinguish not only the physical part of the body, but also some very important thing. So those elder people who live in this area believes, 'Rajagiriya' word was made because of its importance in the Kingdom of Kotte. The house was later purchased by Anagarika Dharmapala. The Hewavitharana Textile Training School was built within the grounds and later Hewavitharana Maha Vidyalaya. The house and the truncated lands were later acquired by the Obeyesekere family and it is generally known as the 'Obeyesekere Walauwa'. The area developed because of plumbago, which was shipped up the canal network from Ingiriya in the Kalutara district for purification at the Welikada graphite works. The area around the Ethul Kotte bridge became a light industrial area, with the 'Electroplastics' and 'Pinnacle' factories and the Ceylon Transport Board's ticket machine workshops. Several historic buildings in the area have been destroyed. These include the ancient Ambalama'' and the 'Welikada Hotel and Bakery' at the Welikada junction, The 'Shermila' cinema and several old houses. Many of the area's marshes, which were the habitat of birds within the Sri Jayawardenapura KotteBird Sanctuary, and which were designated as flood-retention areas, were filled up and built on in spite of the protests of the residents. In the late 1970s the government of JR Jayawardene ran a major road through the very middle of the EW Perera Park.
Areas in Rajagiriya
The Sri Jayawardenapura Kotte municipal ward of Rajagiriya is confined to the areas around the original grounds of the Governor's house. The Rajagiriya postal area also includes Kotiyagoda and Kalapaluwawa within the Kaduwela Pradeshiya Sabha council limits. Rajagiriya within the Kotte municipal limits comprises:
