 As the kingdom pushed west it came under attack from Turkic and Afghan rulers; and on one occasion the Ahoms general Ton Kham Borgohain pursued retreating invaders through a nascent Koch kingdom and reached the Karatoya river—and since then they began to see themselves as the rightful heir of the erstwhile Kamarupa kingdom.From the beginning the relationship between the Ahoms and the Mughals was hostile and that was due to certain factors, such as, Mughal alliance with Koch Bihar, the western enemy of the Ahoms and secondly the growing advance of the Mughals in north-eastern frontier which alarmed them.While the Mughals supported Lakshminarayan, son of Nara Narayan of Koch Behar, the Ahom king Sukhaamphaa (1552–1603) entered into alliance by marrying the daughter of Lakshminarayan's cousin Raghudeva, the son of Chilarai who became the ruler of the eastern part of the kingdom, Koch Hajo which approximately included the modern districts of Goalpara, Barpeta, Kamrup, Darrang and a part of Sonitpur (up to Bharali).