Not all Muslim invaders were simply raiders. Later rulers fought on to win kingdoms and stayed to create new ruling dynasties. The practices of these new rulers and their subsequent heirs (some of whom were born of Hindu wives of Muslim rulers) varied considerably. While some were uniformly hated, others developed a popular following. According to the memoirs of Ibn Battuta who traveled through Delhi in the 14th century, one of the previous sultans had been especially brutal and was deeply hated by Delhi's population. His memoirs also indicate that Muslims from the Arab world, Persia and Turkey were often favored with important posts at the royal courts suggesting that locals may have played a somewhat subordinate role in the Delhi administration. The term "Turk" was commonly used to refer to their higher social status. However S. A. A. Rizvi points to Muhammad bin Tughlaq as not only encouraging locals but promoting artisan groups such as cooks, barbers and gardeners to high administrative posts. In his reign, it is likely that conversions to Islam took place as a means of seeking greater social mobility and improved social standing.