Definition of Extent In Chief
In old English law, a summary process by which the king’s action was commenced against his debtor and his body, personal property (tangible and intangible), and lands at once seized for the satisfaction of the king’s debt. The principal kind of extent, issuing at the suit of the crown, for the recovery of the crown’s debt. Abolished by Crown Proceedings Act (1947). An adverse proceeding by the king, for the recovery of his own debt.
That's the definition of Extent In Chief in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.