Historically, many rulers have assumed titles such as son of God, son of a god or son of heaven. Historically, many rulers have assumed titles such as son of God, son of a god or son of heaven. The term 'son of God' is sometimes used in the Old and New Testaments of the Christian Bible to refer to those with special relationships with God. In the Old Testament, angels, just and pious men, and the kings of Israel are all called 'sons of God.' In the New Testament, Adam, and, most notably, Jesus Christ are called 'son of God,' while followers of Jesus are called, 'sons of God.' In the New Testament, 'Son of God' is applied to Jesus on many occasions. Jesus is declared to be the Son of God on two separate occasions by a voice speaking from Heaven. Jesus is also explicitly and implicitly described as the Son of God by himself and by various individuals who appear in the New Testament. As applied to Jesus, the term is a reference to his role as the Messiah, the King chosen by God. The contexts and ways in which Jesus' title, Son of God, means something more than or other than Messiah remain the subject of ongoing scholarly study and discussion. The term 'Son of God' should not be confused with the term 'God the Son' (Greek: Θεός ὁ υἱός), the second Person of the Trinity in Christian theology. The doctrine of the Trinity identifies Jesus as God the Son, identical in essence but distinct in person with regard to God the Father and God the Holy Spirit (the first and third Persons of the Trinity). Nontrinitarian Christians accept the application to Jesus of the term 'Son of God', which is found in the New Testament, but not the term 'God the Son', which is not found in any part of the Bible. Throughout history, emperors and rulers ranging from the Western Zhou dynasty (c. 1000 BC) in China to Alexander the Great (c. 360 BC) to the Emperor of Japan (c. 600 AD) have assumed titles that reflect a filial relationship with deities. The title 'Son of Heaven' i.e. 天子 (from 天 meaning sky/heaven/god and 子 meaning child) was first used in the Western Zhou dynasty (c. 1000 BC). It is mentioned in the Shijing book of songs, and reflected the Zhou belief that as Son of Heaven (and as its delegate) the Emperor of China was responsible for the well being of the whole world by the Mandate of Heaven. This title may also be translated as 'son of God' given that the word Ten or Tien in Chinese may either mean sky or god. The Emperor of Japan was also called the Son of Heaven (天子 tenshi) starting in the early 7th century. Among the Steppe Peoples, there was also a widespread use of 'Son of God/Son of Heaven' for instance, in the third century BC, the ruler was called Chanyü and similar titles were used as late as the 13th century by Genghis Khan. Examples of kings being considered the son of god are found throughout the Ancient Near East. Egypt in particular developed a long lasting tradition. Egyptian pharaohs are known to have been referred to as the son of a particular god and their begetting in some cases is even given in sexually explicit detail. Egyptian pharaohs did not have full parity with their divine fathers but rather were subordinate.:36 Nevertheless, in the first four dynasties, the pharaoh was considered to be the embodiment of a god. Thus, Egypt was ruled by direct theocracy, wherein 'God himself is recognized as the head' of the state. During the later Amarna Period, Akhenaten reduced the Pharaoh's role to one of coregent, where the Pharaoh and God ruled as father and son. Akhenaten also took on the role of the priest of god, eliminating representation on his behalf by others. Later still, the closest Egypt came to the Jewish variant of theocracy was during the reign of Herihor. He took on the role of ruler not as a god but rather as a high-priest and king. Jewish kings are also known to have been referred to as 'son of the LORD'.:150 The Jewish variant of theocracy can be thought of as a representative theocracy where the king is viewed as God’s surrogate on earth. Jewish kings thus, had less of a direct connection to god than pharaohs. Unlike pharaohs, Jewish kings rarely acted as priests, nor were prayers addressed directly to them. Rather, prayers concerning the king are addressed directly to god.:36–38 The Jewish philosopher Philo is known to have likened God to a supreme king, rather than likening Jewish kings to gods.