Megasthenes was the Greek ambassador sent by Seleucus Nicator to the court of Chandragupta Maurya. He wrote the book 'Indica'.

Chandragupta Maurya defeated Dhana Nanda, the last ruler of the Nanda dynasty, to establish his own empire in Magadha.

Chandragupta Maurya founded the Mauryan Empire around 322 BCE by overthrowing the Nanda dynasty with the help of his mentor, Chanakya.

While 'Om' appears in Vedas, the Mandukya Upanishad is entirely devoted to the exposition of the syllable 'Om'.

Brahmavarta was the holy land between the rivers Saraswati and Drishadvati, considered the center of Vedic culture.

The Hotri was the priest responsible for invoking the gods by reciting hymns from the Rigveda. Udgatri was for Samaveda, Adhvaryu for Yajurveda, and Brahma for Atharvaveda.

The four Ashramas (Brahmacharya, Grihastha, Vanaprastha, Sannyasa) as a structured system of life stages developed during the Later Vedic period.

Lopamudra (wife of Sage Agastya) is a prominent female sage (Rishika) whose hymns are found in the Rigveda. Gargi and Maitreyi appear in the later Upanishads.

Since cows were the main form of wealth, wars were often fought to acquire them. 'Gavisthi' literally means 'search for cows' but came to mean 'to fight' or 'war'.

Rudra, a storm god associated with wind and healing/disease in the Rigveda, is considered the early form or precursor of Lord Shiva.