How Dharmic religions originated and when?

Dharmic religions are one of the three main schools of religion in the world (the others being the Abrahamic religions, which include Christianity, Islam, and Judaism, and the Taoic religions, which include Caodaism, Chondogyo, Confucianism, Shinto, and Taoism).

The Dharmic religions all originated in the Indian subcontinent, but have subsequently all spread to other regions round the world, especially to Southeast and East Asia.

All the Dharmic religions generally center around the concept of Dharma, a Sanskrit word (Sanskrit was an ancient language spoken in India), meaning law, duty or fixed decree.

The largest Dharmic religions include:

Buddhism

Buddhism is a non-theistic religion based on the the teachings of Siddharta Gautama, known as the Buddha. Various forms of Buddhism are widely practiced around Asia, and have also spread to Western countries too.

Hinduism

Hinduism is the oldest living religion in the world, with roots going back to at least 2,500 BCE. Hinduism is the largest religion in India, but is practised in other countries too.

Jainism

Jainism is another religion with ancient Indian roots. The number of adherents to Jainism is relatively small, but Jain communities can be found both in India and in other countries.

Sikhism

Sikhism is a religion that began in Northern India, and is based on the teachings of Guru Nanak Dev (1469 to 1539) and subsequent Sikh gurus. The largest Sikh community is found in the Punjab region of India, but there also Sikh communities in other parts of India, as well as in other countries.