Rajpurohit (राजपुरोहित) is both a direct lineage of the ancient sages often delegated to the ancient Kings for royal advice and also a subgroup of Hindu Brahmins (Brāhmaṇa,ब्राह्मणः) with its roots in Rishikul (great revered Indian sages from Vedic era) and later Brahaminical Gupta period in India. All brahami has origanally seven gotra came from seven Rishi.With the Brahaminical distinction of a class & caste system in the 'Dharma' hierarchy, the 'Brahamin Rajpurohits' of the Rishi lineage performed royal rituals while the 'Kshatriya' trained under the sages performed martial duties for the welfare & protection of the kingdom. The name of the sage was annexed as a 'gotra' to identify either the origin of lineage,training or even protection (Kayastha)under the sages.The 'Royal priests' are considered as the oldest Brahmins who were associated with the ruling class of a kingdom since ancient ages in India. In the course of history the 'Rajpurohits' were not only involved in heading the religious rites and duties, but some 'Kshatriyas' having trained in the duties of the various 'Dharma', including martial arts, termed themselves as 'Rajpurohitis' and provided selfless service to the state, they were considered to be guardians of the state. They were as much into mentoring royal house, educating princes, guiding king on the path of dharma, providing advise on the matters of welfare of the state, performing religious duties as they were into helping in maintaining the security of kingdom by being actively involved in battles. Guru Dronacharya and Kripacharya were the Rajpurohits of the ancient kingdom of Hastinapur who participated in the great war of Mahabharata on behalf of the state during fall of the Dvapara Yuga. Present day Rajpurohits also trace this spirit of martial hood from the great Brahmin warrior sage Parashurama. As an example, the Junagarh fort in Bikaner houses memorial of Jagram ji Rajpurohit who died fighting for the cause of the state. As a custom, every wedding in the royal family of Bikaner is incomplete without paying homage to him. Such cenotaphs and headstones of Rajpurohits can be found all over Marwar and Bikaner. Chanakya (Sanskrit: चाणक्य Cāṇakya) (c. 350-283 BCE) was an adviser, a prime minister and Rajpurohit to the first Maurya Emperor Chandragupta (c. 340-293 BCE), and architect of his rise to power. Similarly the Vatsayana sage lineage originated from Banares in the 1st century for Vedic rituals & gave advice to the kings in the Himalyan belt to convert the pagan tribals to a vedic tradition.The Vatsayana lineage attempted to introduce the 'Tantric' worship in the legend of Tara & Kameke. Along with the other surnames like Vatsayans, Dixit,Sharma, Goswami etc., Purohit/Rajpurohit is also used as a surname among the Brahmins.