 Complete the following phrase:  There were quantitative reasons for this date of origin. Tsar Alexander II was assassinated by a bomb on March 13, 1881, and ushered in a wave of official and popular antisemitic violence known as pogroms in which individuals were killed, cultural institutions sacked, and property destroyed. The reaction raged at its most extreme in the years 1881 and 1882, during which there were scores of violent events throughout the southern and western 