Zugot
Zugot (Hebrew: תְּקוּפַת ) הַזּוּגוֹת ), (təqûphāth) hazZûghôth) refers to the period during the time of the Second Temple (515 BCE – 70 CE), in which the spiritual leadership of the Jewish people was in the hands of five successive generations of zugot ("pairs") of religious teachers.
Read more about Zugot.