Many years ago there was a large Jewish population in Babylon. The Jewish community there were descendants of the first exiles whom Nebuchadnezzar, King of Babylon, had exiled even before the destruction of the first Holy Temple in 422 BCE—the Exile of Jechoniah. Fifty years after the destruction, Cyrus, King of Persia (a world famous ruler in those days), permitted the Jews to return to their homeland. At the head of those who returned from Babylon was Zerubabel ben Shealtiel, a descendant of King Jechoniah, who was one of the last kings of the House of Judah in Eretz Yisroel. Many Jews returned to Eretz Yisroel, but many Jews remained in Babylon.

Zerubabel's family in Babylon, who were descendants of the royal house of King David, enjoyed special respect and honor from the royal family of Persia. It was from this family that the King, with the assent of the Jews, chose a "Leader of the Exile", the Jewish representative at the Persian Court and the highest position among exiled Jews in Babylonia. King Cyrus recognized Zerubabel as governor of Eretz Yisroel.

After the destruction of the Second Holy Temple in 3828 (68 CE) by wicked Titus of Rome, many Jews again escaped to Babylon, and there the Jewish community grew even more significant. There were Yeshivot (Talmudical Academies), where thousands of students studied the Holy Torah at the feet of the wise men of Babylon. There, the Tanaim and later the Amoraim, Rabonon Saborai and Gaonim, lit up the dark Jewish exile with the radiant light of the Torah.

Up to the time of Rav Saadiah Gaon, who died in the year 4702 (942 CE), the position of the "Leader of the Exile" was handed down from father to son, as with royalty. During those years, the "Leader of the Exile" stood at the head of the Babylonian Jewish community, protecting the rights of the Jews in their adopted country and easing their financial situation. He also played the role of spiritual leader of the Jews, because he was the greatest Torah authority of his time.

One of the best-known "Leaders of the Exile" was Bustenai ben Chaninah. The following story is told about how Bustenai became "Leader of the Exile":

At that time a cruel Persian king persecuted the Jews. He especially persecuted the family of the "Leader of the Exile", and he murdered as many members of the descendants of King David as he could locate. The most prominent members of the Jewish community were thrown into prison, and the Jewish situation in Babylon was indeed grim.

However, one lady, a descendant of King David and ready to give birth, saved herself by going into hiding. Meanwhile, the king made extensive inquiries to determine if members of the royal house of King David remained alive. Then the king dreamt that he was standing in a beautiful garden, where the loveliest trees and fruits were blooming. He was holding an ax, chopping down the trees one after another. Suddenly, he noticed a sapling, hidden in a corner of the garden, and gave a swing with the ax. A strong hand then gripped his arms, preventing him from continuing. Turning around, the king saw an old man with a G‑dly appearance. The old man grabbed the ax out of the king's hand and threatened to kill the king with it. Terrified, the king threw himself at the feet of the old man and begged him to let him live.

"Why should I have mercy on you, when you have no mercy on the innocent trees?" the old man said sternly to the king, and paused. "I will let you live on one condition: you must guard this sapling as the apple of your eye till it grows into a tree and gives forth fruit!" The king swore that he would fulfill this condition … and then suddenly awoke from his sleep.

In dread fear, he called together his advisers and told them of his dream, but none of them could interpret it for him. One of his servants then called out, "My lord! Many Jewish wise men are locked in prison. The king can certainly find among them one who can interpret the dream correctly."

The king agreed and ordered his servants to bring before him the Jewish captives, to whom he told his dream.

The oldest of the Jewish captives interpreted the dream immediately.

"The trees in the garden represent the House of David, whom the king so mercilessly and ruthlessly murdered. The sapling that the king wanted to chop down represents the last remaining descendant of King David, soon to be born. And the old man you saw in the dream is King David himself, who came to save his last remaining heir. If the king wishes to remain alive, he must unfailingly keep his promise. He must find the lady who will soon bear a son and see that no harm should befall her, as the king's life depends on her!"

"But where can I find this lady?" the king asked, shaking with fear.

"I can find her," the old man replied, with tears in his eyes. "She is my daughter. My son-in-law was a member of King David's family and was murdered. My daughter therefore went into hiding for fear of the king."

Immediately, the king ordered the release of all the Jewish captives. He asked the old man to bring his daughter to the king so he could take care of her and guard her as the apple of his eye.

Soon the lady gave birth to a son who grew up under the king's watchful eye. His mother and grandfather taught him and raised him to become a worthy "Leader of the Exile." Everybody called him "Bustenai" from the word bustan, meaning "a garden". When Bustenai grew up, the king appointed him "Leader of the Exile" with the Jews' assent. He gave him much honor and power, such as no "Leader of the Exile" had ever enjoyed.