In 477 AD, after a coup supported by Migara, the King's nephew and commander of the army, Kashyapa I, the son of the king by a non-royal consort, seized the throne from King Dhatusena. The rightful heir Moggallana fled to South India, fearing for his life. Fearful of an attack by Moggallana, Kashyapa moved from the traditional capital of Anuradhapura to the more stable Sigiriya, the capital and its home. Sigiriya was turned into a complex town and fortress during the reign of King Kashyapa (495 AD). The majority of the elaborate buildings on and around the rock summit, including defensive structures, palaces, and gardens, date from this time.
King Kashyapa is identified by the Culavamsa as King Dhatusena 's son. Kashyapa killed his father by walling him up alive and then usurping the throne that rightly belonged to his half-brother Moggallana, the real queen 's son of Dhatusena. Moggallana fled to India to escape Kashyapa 's assassination but vowed vengeance. He raised an army in India with the intention to return and reclaim Sri Lanka 's throne, which he rightly considered to be his.In anticipation of Moggallana's imminent return, Kashyapa is said to have constructed his palace as both a fortress and a palace of pleasure on top of Sigiriya. Moggallana eventually arrived, declared war, and in 495 AD defeated Kashyapa. The armies of Kashyapa deserted him during the battle and he committed suicide by falling upon his spear.
The Culavamsa and folklore tell us that the battle-elephant mounted on Kashyapa changed direction to take a strategic advantage, but the army misinterpreted the movement as the king decided to withdraw, causing the army to completely abandon it. It's said to be too proud to surrender he took his dagger out of his waistband, cut his throat, proudly raised the dagger, sheathed it, and fell dead.Moggallana restored the capital to Anuradhapura, transforming Sigiriya into a complex of the Buddhist monasteries that lasted until the 13th or 14th century. No records are found on Sigiriya after this period until the 16th and 17th centuries, when it was briefly used as an outpost of the Kingdom of Kandy.
The site plan is thought to be very elaborate and imaginative. The strategy merged principles of symmetry and asymmetry to intentionally interlock with existing man-made geometric and natural forms. There is a royal park on the west side of the rock, laid out on a symmetrical plane; the park includes water-retaining facilities, including advanced hydraulic surface / surface systems, some of which are actually operating. The south features a man-made reservoir; these have been used extensively from Sri Lanka 's previous dry zone capital. There were five gates at the entrances.
One of the most important features of the site is the Sigiriya City Gardens, since it is among the world's oldest landscaped gardens. The gardens are divided into three distinct but interconnected forms: water gardens, cave and boulder gardens, and garden terraces.