And I ll repeat the criterion and not my criterion for judging a scholar in the field which I believe is actually the Wikipedia criterion It is very simple Savory has written dozens of articles with regards to Safavid history in peer reviewed journals he has written books that are cited by scholars on the subject and furthermore he is the one that wrote most of the Safavid related articles in Iranica Encyclopedia of Islam and Cambridge history of Iran and etc So no all historians and Tapper is not a historian do not have equal weight when there is a contradiction For example Minorsky and Savory have less weight on Achaemenid Iran and Briant and Shahbazi and Frye would be better On Sassanid Iran it is Frye Daryaee Christensen although a bit out dated now and others On Shadadids that would be Minorsky and not for example Savory The criterion for judging is objective The number of articles books and etc written by the author on the specific subject But in case of a contradiction I do not necessarily go with the scholar who has more weight and I try to first examine the primary source In this case the Alem Araay Abbassi I believe explains how Esmail I was crowned and what he said