Tanna who had the task of reconstructing the fabric of Jewish life after the destruction of the Second Temple in 70 C.E.. He was one of the youngest of Hillel’s pupils who according to tradition lived until the age of 120. He issued ten important and urgently needed ordinances in order to adapt Jewish life and halakha to the new reality and perpetuate the memory of the Temple until such a time as it could be rebuilt. The very fact that Jews were able to nurture and develop their national and cultural life in the 2,000 years that followed attests to the success of his endeavors.
Read more in the Jewish Encyclopedia .