The Indian Massacre of 1622 took place in the English Colony of Virginia, in what is now the United States, on Friday, 22 March 1622. John Smith, though he had not been in Virginia since 1609 and was not a first hand eyewitness, related in his History of Virginia that braves of the Powhatan "came unarmed into our houses with deer, turkeys, fish, fruits, and other provisions to sell us". The Powhatan grabbed any tools or weapons available and killed all English settlers they found, including men, women, and children of all ages.  Chief Opechancanough led a coordinated series of surprise attacks by the Powhatan Confederacy that killed 347 people, a quarter of the English population of the Virginia colony. Jamestown, founded in 1607, was the site of the first successful English settlement in North America, and was then the capital of the Colony of Virginia. Its tobacco economy led to constant expansion and seizure of Powhatan lands, which ultimately provoked a violent reaction.
Question: What was the cause of violence from the Powhatan tribes?
Answer: seizure of Powhatan lands