The Tughlaq dynasty lasted from 1320 to nearly the end of the 14th century. The first ruler Ghazi Malik renamed himself Ghiyath al-Din Tughlaq and is also referred to in scholarly works as Tughlak Shah. He was of "humble origins" but generally considered of a mixed Turko-Indian people. Ghiyath al-Din ruled for five years and built a town near Delhi named Tughlaqabad. According to some historians such as Vincent Smith, he was killed by his son Juna Khan, who then assumed power in 1325. Juna Khan renamed himself Muhammad bin Tughlaq and ruled for 26 years. During his rule, Delhi Sultanate reached its peak in terms of geographical reach, covering most of the Indian subcontinent.