When was the Jewish law created?

Tradition holds that the Torah was first written down by Moses around 1300 BCE (Deuteronomy 31:24). Modern secular scholars suggest it may have been an oral tradition that was not written down until a few centuries later.

The Oral Torah was handed down orally, from the time of the Revelation at Mount Sinai (Pirkei Avot ch.1) until it was put in writing some 1500 years ago.