According to 2 Kings 25:1–25, on the 10th day of the 10th month of Tevet,[note 2] in the ninth year of Zedekiah's reign (588 BCE), Nebuchadnezzar II, the second Neo-Babylonian emperor, began the siege of Jerusalem.
Eighteen months later, on the 17th of Tammuz at the end of the eleventh year of Zedekiah's reign (586 BCE), he broke through the city walls.
One opinion in the Talmud [4] states that the "fast of the tenth month" refers to the fifth of Tevet, when, according to Ezekiel 33:21, news of the destruction of the Temple reached those already in exile in Babylon.
According to tradition, as described by the liturgy for the day's selichot, the fast also commemorates other calamities that occurred throughout Jewish history on the Tenth of Tevet and the two days preceding it: Judaism sees this event as a tragedy, reflecting a deprivation and debasement of the divine nature of the Torah and a subversion of its spiritual and literary qualities.
Its divergence from the accepted text (afterward called the Masoretic) was too evident; and it therefore could not serve as a basis for theological discussion or for homiletic interpretation.
[8]As with all minor ta'anit (Jewish days of fasting), the Tenth of Tevet begins at dawn (alot ha-shahar) and concludes at nightfall (tzeit hakochavim).
[18] The Chief Rabbinate of Israel chose to observe the Tenth of Tevet as a "general Kaddish day" (yom hakaddish ha'klalli) to allow the relatives of those whose yahrtzeit (anniversary of their death) is unknown, including Holocaust victims, to mourn their loss.
[19][20] Relatives may observe the traditional yahrtzeit practices for the deceased, including lighting a memorial candle, learning mishnayot, and reciting Kaddish.
According to the policy of the Chief Rabbinate in Israel, the memorial prayer is also recited in synagogues after the reading of the Torah at the morning services.