13. Kashyapa I of Sri Lanka murdered his father by sealing him inside a wall, before being overthrown by his half-brother and the rightful heir
Kashyapa I (b. date unknown) was the second king of the Mauryan dynasty of Sri Lanka, ruling as King of Sinhala from 473 to 495 CE. Although the eldest son of King Dhatusena, as Kashyapa was not the son of a royal consort, instead of a non-royal concubine, his younger brother Moggallana was the rightful heir to the throne. Dissatisfied by this arrangement, Kashyapa formed an alliance with the commander of the royal army, Migara, and initiated a palace coup to overthrow his father in 473 CE. Misled that Dhatusena had hoarded a vast treasure, upon realization that this supposed wealth was a technologically advanced irrigation tank Kashyapa murdered his father by entombing him inside a wall; following this event, Kashyapa was popularly known as “Pithru Ghathaka Kashyapa” (Kashyapa the Patricide).
Despite a prolonged period as ruler, during which time the impressive Sigiriya citadel and elaborate surrounding city was constructed for his capital, Kashyapa’s half-brother Moggallana never capitulated, choosing instead flight into exile and in 495 CE returned to Sri Lanka with an army to claim his rightful throne; in the resultant battle, Moggallana’s army proved victorious and in defeat Kashyapa threw himself upon his own sword.