Dipendra of Nepal
Dipendra Bir Bikram Shah (27th June 1971 - 4th June 2001) was Crown prince of Nepal until June 2001, when he became de facto king for three days after he killed the rest of his family during the Nepalese royal massacre.
On 1st June 2001, Crown Prince Dipendra opened fire in the grounds of the Narayanhity Royal Palace, the official residence of the Nepalese monarchy, while a party was being held. He killed his father, King Birenda, his mother, Queen Aishwarya, his brother, Prince Nirajan, his sister, Princess Shruti, his uncles, Prince Dhirendra and Kumar Khadga, his aunts, Princess Shanti and Princess Sharada, and his father's cousin, Princess Jayanti. He also wounded his aunt, Princess Shova, his brother-in-law, Kumar Gorakh, the future Queen, Princess Komal, and his father's cousin, Ketaki Chester. He then collapsed from a bullet wound to the head. An investigation would claim that he committed suicide, but this claim remains disputed, as he was right handed, but the bullet wound was on his left side. He slipped into a coma, and was pronounced de facto ruler of Nepal, with his uncle Gyanendra as regent until he emerged from his coma. However, he died three days after his appointment, and Gyanendra was pronounced king.
Dipendra's motive for the massacre remains unknown. Theories include that he was angry that his parents refused to let him marry Devyani Rana, and that he believed his family had given too much power to the people, although the second is unlikely, as Dipendra was a supporter of the People's Rights Movement.