Killing in the Name of Establishing Hinduism

📖Brahmanda Purana Section 2 – Anuṣaṅga-pāda, Chapter 31 Verses 77-84
In the previous Svayambhuva Manvantara, he had been born of a part of Madhava (Visnu). For a full period of twenty years, he wandered over the Earth taking with him an army along with horses, chariots and elephants. Surrounded by hundreds and thousands of Brahmanas wielding weapons, he killed all the Mlecchas all round along with those kings, the heretics born of Sudra women. The lord exterminates those heretics. Everywhere he kills all those who are not scrupulously religious. The lord who was strong and who annihilated all the Mlecchas slew these also People who were born of parents of different castes, those who depended on them, the Udicyas (Notherners), Madhya Desyas (Persons of middle lands), Parvatiyas (Mountain-dweller), Pracyas (Easterners), Praticyas (Westerners), those who talk about on the ridges of the Vindya mountains, Daksinatyas (Southerners), Dravidas along with Simhalas (Ceylonese), Gandhara, Paradas, Pahlavas, Yavanas, Sakas, Tusaras. Barbaras, Cinas (Chinese), Sulikas, Daradas, Khasas, Lampa-karas, Katakas and different tribes of Kiratas. The powerful lord wielding the discuss slew all these barbarous 

Reference : Brahmanda Purana Section 2 – Anuṣaṅga-pāda, Chapter 31 Verses 77-84

Additional Information

The verses you have cited describe the actions of a previous Manu, or cosmic patriarch, during his reign. According to the text, he led a military campaign across the earth, accompanied by an army and Brahmins wielding weapons. He is said to have killed various groups of people, including “Mlecchas” (a term that can have different meanings in different contexts, but generally refers to non-Hindus or people considered impure or uncivilized), heretics born of Sudra women (who were considered of lower caste and not allowed to perform certain religious rites), and people of various regional and ethnic backgrounds. In this passage Manu’s goal was to establish Hinduism, although it does emphasize the importance of religious observance and the punishment of those who do not follow religious rules. It is also important to note that the Brahmanda Purana is just one of many Hindu scriptures, and its teachings and historical accounts may not be universally accepted by all Hindus.