"EC2" wrote: Of course he was acting within the parameters of society at the time with his attitudes, but even within that society, some were more extreme than others, and his were at the extreme end. There were degrees of tolerance too.
I think that is very much the point EC. Jews in Europe throughout the middle ages, were isolated by the Christians and exposed to their fanatical hatred as the 'murderers of Christ!' The Crusaders in Germany in 1096, for example, were said to have massacred thousands of Jews in preparation/practice for massacring the Moors when they arrived in the Holy Land!
I do not want to be an apologist for Simon de Montfort, but he was hardly alone in his treatment of the Jews in England. He certainly expelled them from his town of Leicester in 1231 (not aware if this was accompanied by any killings), but it was Edward 1 who expelled them all from England in 1290, long after Simon's death (they were only formally accepted back in England in 1655, some 350 years later!).
I can understand your friend, as a Jew, despising Simon, but that would probably hold true for his opinion of any number of English historical figures. Let's see what this author's take on the subject will be!