Useful reference for spread of Islam and Islamic history with a very specific character as a "dateline" reference of dynasties and history year by year and by various regions of islamic world.Some specialists would criticize particular points but it remains a useful resource both to get condensed view of a period and area of the Muslim world and as a way of reviewing details after reading broader and more interpretive works. Many readers will want to have some version of the Encylopedia of Islam available to get further information on specific terms and issues.