Did Chanakya really write the Arthashastra for Chandragupta Maurya?

Probably not, at least not alone and not in his lifetime. Gupta-era and medieval traditions identified the Arthashastra's author, Kautilya, with Chanakya, the legendary counsellor of Chandragupta Maurya. But that identification has been questioned by scholarship and rejected by the main studies on the topic since 1965, because the text's shifting styles point to several authors and some of its historical details do not fit the Mauryan period. The surviving text was most likely completed between the 1st and 3rd century CE, centuries after Chandragupta.

The legend has a real emperor behind it. Chandragupta Maurya, who reigned from about 320 BCE to about 298 BCE, founded the Maurya Empire, based in Magadha, in the unrest after Alexander the Great's Indian campaign and early death in 323 BCE. He defeated the unpopular Nanda dynasty and raised an army to resist the Greeks. According to the play Mudrarakshasa, he was assisted by his mentor Chanakya, who later became his minister.

The book itself is an ancient Sanskrit treatise on statecraft, politics, economic policy and military strategy, likely the work of several authors over centuries, starting as a compilation of earlier Arthashastras. It was influential until the 12th century, when it disappeared. In 1905 a palm-leaf copy was presented to the newly opened Mysore Oriental Library, where the librarian R. Shamasastry recognised it, and he published it in 1909.

Whoever wrote it, it is a window into how ancient Indian thinkers believed a state should be run: it advises a king to start public works and lift taxes in areas struck by famine or war, and devotes many chapters to a network of spies.