The Baro-Bhuyans (or Baro-Bhuyan Raj; also Baro-Bhuians and Baro-Bhuiyans) refers to the confederacies of soldier-landowners in Assam and Bengal in late middle age and early modern period. The confederacies consisted of loosely independent entities, each led by a warrior chief or a landlord (zamindars). The tradition of Baro-Bhuyan is peculiar to both Assam and Bengal and differ from the tradition of "Bhuihar" of Uttar Pradesh and Bihar—in Assam this phenomenon came into prominence in the 13th century when they resisted the invasion of Ghiyasuddin Iwaj Shah and in Bengal when they resisted Mughal rule in the 16th century.