Who was Sri Narayana Guru and what was his contribution?

Sri Narayana Guru was a philosopher, spiritual leader and social reformer in India. He led a reform a successful movement against the injustice in the caste-ridden society of Kerala in order to promote spiritual enlightenment and social equality

For further reading check the following articles:

• List of Socio-Religious Movements
• Dayananda Saraswati – Arya Samaj
• Indian Education System During British Rule