Beginning of Judaism as a structured religion (before 164 BCE): The Jews, under God’s guidance became a powerful people with kings such as Saul, David, and Solomon, who built the first great temple.
From then on Jewish worship was focused on the Temple, as it contained the Ark of the Covenant, and was the only place where certain rites could be carried out. (BBC)
Temple Destruction: "The first revolt, in 70 CE, led to the destruction of the Temple. This brought to an end the temple worship and is still perceived by traditional Jews as the biggest trauma in Jewish history. It is marked by the fast day of Tisha B'av (meaning the ninth day of the month of Av)." (BBC)