Prince Al-Waleed bin Khaled bin Talal Al Saud, popularly known as Saudi Arabia's 'Sleeping Prince', has passed away after spending two decades in a coma. Belonging to the House of Saud, he was the great-grandson of King Abdulaziz, founder of modern Saudi Arabia, and grandson of Prince Talal bin Abdulaziz. The current monarch, King Salman bin Abdulaziz, is his great-uncle.