In the sixteenth century, Scottish farmers owed rent payment to English landlords. This rent could be paid in White Mail–silver, or it could be paid by Black Mail.
Black Mail was when farmers would exchange goods or livestock for their right to dwell on the land. Black mail took on the negative connotation associated with it today when the English grew greedy. The landlords would often charge more in Black Mail than they would in White Mail, taking advantage of their tenants.