'''Tithe Grade''' , also named the '''Great Harvesting''' or '''Terra's Due'''² refers to the amount of materials an Imperial world must supply to the [[Administratum]]. The size of the tithe depends on the type of world it is applied to. A tithe can be any form of material: food, weapons, minerals, people, etc..

It is the duty of [[Space Marine]] [[homeworldPlanetary Governor]]'s do not normally have tithesto ensure the tithe of their world is paid, and are given any world which fails to pay its tithe meets with vicious reprisal from the tithe grade [[Aptus NonAdeptus Terra]].However as long as the planetary ruler dutifully pays his worlds tithe, he may rule the planet in almost any way he sees fit.²

[[Space Marine]] [[homeworld]]s do not normally have tithes, and are given the tithe grade [[Aptus Non]] while [[Agri world]] tithes generally refer to how much of the planet's food production must be supplied.