What is this between the Sunnis and Shias?

Watch this video done on the Shia-Sunni historical split by Lesley Hazleton an agnostic Jew. Her book is well respected and found here.

Although some parts of this video may be historically controversial (or wrong), it provides an interesting description of some aspects of Shia and Sunni from a Jewish perspective. An example of the historically controversial is that all (Imam) Hussain’s companions died at the day of Ashura (10th day) from morning to around noon, whereas based on the video, most companions died before Ashura and then at (Imam) Hussain dies at Ashura.