 However, following Ismail II's short and bloody reign Mohammad emerged as the only heir, and so with the backing of the Qizilbash tribes became Shah in 1578.Mohammad's reign was marked by a continued weakness of the crown and tribal infighting as part of the second civil war of the Safavid era.An important figure in the early years of Mohammad's reign was his wife Khayr Al-Nisa Begum, who helped secure her husband's reign.