Nagarjuna was born in South India around 150 CE and became the most important Buddhist philosopher after the Buddha himself. He founded the Madhyamaka (Middle Way) school, which argues that all things are 'empty' of inherent existence. Nothing exists independently; everything arises in dependence on causes and conditions. This is not nihilism. Emptiness is the condition that makes change, growth, and liberation possible. His method was to take any philosophical position and show that it leads to contradiction, leaving only the middle way between extremes.
Born in the Andhra region of South India, probably into a Brahmin family. The details of his early life are buried under layers of legend. Tibetan sources say he lived for six hundred years, which tells you more about his reputation than his biography.