In the middle of the 17th century the Brahuis, with the help of Turks, took advantage of the Balochis weakness after the Rind-Lashari war which lasted for 30 years and had driven them out of the Kalat valley. Yielding to pressure they moved eastward into the Sulaiman Mountains, drove out the Pashtuns, and settled along the banks of the Indus. According to Dr. Akhtar Baloch, Professor at University of Karachi, the Balochis migrated from Balochistan during the Little Ice Age and settled in Sindh and Punjab. The Little Ice Age is conventionally defined as a period extending from the sixteenth to the nineteenth centuries, or alternatively, from about 1300 to about 1850. Although climatologists and historians working with local records no longer expect to agree on either the start or end dates of this period, which varied according to local conditions. According to Professor Baloch, the climate of Balochistan was very cold and the region was inhabitable during the winter so the Baloch people migrated in waves and settled in Sindh and Punjab. The three Baloch adventurers Ismail Khan, Fatteh Khan, and Ghazi Khan, founded the three Dehras (encampments) that bear their names, and established themselves as independent rulers of the Lower Derajat and Muzaffargarh, which they and their descendants held for nearly 300 years. The three brothers founded the settlements of Dera Ghazi Khan, Dera Ismail Khan and Darya Khan. Thence the southern Balochis gradually spread into the valleys of the Indus, Chenab, and Sutlej, and in 1555 a large body of Balochis, under their great leader Mir Chakar, accompanied the Emperor Humayun into India. It is probable that many of the Baloch settlements, in North India (Haryana and western Uttar Pradesh), were founded by Humayun's soldiers. Mir Chakar settled in Sahiwal and his tomb still exists at Satgarha, where he founded a military colony of Rinds.