Keeping the Jubilee year and its attendant laws ended at the time of the exile of the tribes of Re’uven, Gad and half of Menashe, who made their homes on the eastern bank of the Jordan River, an event that took place many years before the destruction of the first Temple. The Rambam explains that the laws of the Jubilee year apply only when the Jewish people are established in the Land of Israel, and since that time this has not been the case. It is clear from a variety of sources that during the second Temple many of the laws relating to the Jubilee year were kept, a fact that led Rabbenu Tam to assume that there was a biblical obligation to keep the yovel during that time. The Rambam does not accept this reasoning, and he states clearly that the laws of yovel did not apply during second Temple times (see the Mishneh Torah, Hilkhot Shemittah ve-Yovel 10:3). Some suggest that there was a Rabbinic injunction to keep some of the laws during the second Temple period.