The Sadducees were an important part of Jewish life for about 300 years just before the destruction of the second (Herod's) Temple in Jerusalem in 70 CE. They were mainly nobles and wealthy merchants. They took their name from Zadok, the first High Priest of ancient Israel to serve in the First Temple.
Ever since the Greeks had conquered the lands of Judea, there had been a shift from the importance of the Temple. The Sadducees were a group who wanted to restore the old order, and they sought to do this by taking control of the Temple and its ceremonies. The trouble was they were also developing a reputation for being corrupt.
When the Romans destroyed Herod's second temple, the Sadducees lost their power base and disappeared from history.