The story of the evolution of Judaism from its origins in the remote past into the complex and various forms by which it is known in the present day does not lend itself to a straightforward historical narrative. The following study attempts to understand how the Second Hebrew Commonwealth came into being and the critical role that Mosaic religion played in the process, which resulted in what may be termed Pharisaic Judaism, which effectively came to an end with the destruction of the Second Temple by the Romans in 70 CE. By the sheer willpower and intellectual ability of the sages who survived the national disaster, Pharisaic Judaism was morphed into Rabbinic Judaism, which ultimately evolved over a period of two millennia into the variety of forms that presently adorn the religious landscape of the Jewish people. Part 1 of this study is concerned with the story of Pharisaic Judaism, which emerged in a period in which the majority of the Jewish people were political factors in the history of the Jewish nation, something that would only emerge once again in the twentieth century with the creation of the modern State of Israel. Ancient Judaea existed in the midst of the region properly known as Cisjordan, the region between the Mediterranean Sea and the Jordan River, which constituted the land-bridge between Africa and Asia, through which the more accessible one of the two primary trade and military routes between Egypt and Mesopotamia passed. This made it a critical chunk of territory, the control of which was a constant objective of contending powers throughout the history of the Middle East, and gave Judaea a strategic importance virtually unrelated to its natural resources or wealth. Accordingly, in presenting the story of Pharisaic Judaism, considerable space will be given to the geopolitics and domestic politics in which the Jewish religious authorities necessarily were deeply involved, as is the case today in modern Israel.