Tao-te ching, translated the Classic of Tao and Te, is a "ching", that is, a book considered to be of a great value in the Chinese tradition (much like the Bible in the Christian
tradition). It is ascribed to Lao-tzu (the Old/Venerable Master).
According to Ssu-ma Ch'ien (historian of the Chinese antiquity), Lao-tzu would have left the sovereign's court, going to West, and met Yin Hsi, the
Guardian of the pass, who asked him to write a book of wisdom. This is how Tao-te ching took birth.
Still there are opinions maintaining that the book is a mere collection of various texts (without relation
with each another) written in different time periods, or even the work of a secret organization of philosophers.
Many assume that Lao-tzu didn't exist.
In short, the history of the book is related to a certain
Lao-tzu, be it a group of persons interested in philosophic matters or a philosopher contemporary with Confucius.
-> Introduction to Tao-te ching by James Legge
-> D C Lau comments on Tao-te ching