Assassination and its merits. In the Old Testament, King Joash of Judah was assassinated by his own servants; Joab assassinated Absalom, King David's son; and King Sennacherib of Assyria was assassinated by his own sons. Chanakya (–283 BC) wrote about assassinations in detail in his political treatise Arthashastra. His student Chandragupta Maurya, the founder of the Maurya Empire, later made use of assassinations against some of his enemies. Some famous assassination victims are Philip II of Macedon (336 BC), the father of Alexander the Great, and Roman dictator Julius Caesar (44 BC). Emperors of Rome often met their end in this way, as did many of the Muslim Shia Imams hundreds of years later. Three successive Rashidun caliphs (Umar, Uthman Ibn Affan, and Ali ibn Abi Talib) were assassinated in early civil conflicts between Muslims. The practice was also well known in ancient China, as in Jing Ke's failed assassination of Qin king Ying Zheng in 227 BC. Whilst many assassinations were performed by individuals or small groups, there were also specialized units who used a collective group of people to perform more than one assassination. The earliest were the sicarii in 6 AD, who predated the Middle Eastern Assassins and Japanese shinobis by centuries. Modern history During the 16th and 17th centuries, international lawyers began to voice condemnation of assassinations of leaders. Balthazar Ayala has been described as "the first prominent jurist to condemn the use of assassination in foreign policy". Alberico Gentili condemned assassinations in a 1598 publication where he appealed to the self-interest of leaders: (i) assassinations had adverse short-term consequences by arousing the ire of the assassinated leader's successor, and (ii) assassinations had the adverse long-term consequences of causing disorder and chaos. Hugo Grotius's works on the law of war strictly forbade assassinations, arguing that killing was only permissible on the battlefield. In the modern world, the killing of important people began to become more than a tool in power struggles between rulers themselves and was also used for political symbolism, such as in the propaganda of the deed. In Japan, a group of assassins called the Four Hitokiri of the Bakumatsu killed a number of people, including Ii Naosuke who was the head of administration for the Tokugawa shogunate, during the Boshin War. Most of the assassinations in Japan were committed with bladed weaponry, a trait that was carried on into modern history. A video-record