Wills are an excellent source for the history of how people used to live in Hartley. They give an idea of the relative standing of the person, and tell us of their families.
They survive for Hartley from about 1450 onwards. Depending on where the will was "proved" it will be filed at:
Centre for Kentish Studies (CKS/KAO) - all wills proved at the court of the Archdeacon or Bishop of Rochester (pre 1858)
The National Archives (TNA/PRO) - all wills proved at the court of the Archbishop of Canterbury (pre 1858).
Principal Probate Registry - all wills proved after 1858.
There are also a few "Inquisitions Post Mortem" (pre 1660). These are local enquiries held when a tenant of the crown died, to see if anything was owed to the monarch.