In Anglo-American law, the method by which a debtor (mortgagor) conveys an interest in property to a creditor (mortgagee) as security for the payment of a money debt.
The modern mortgage has its roots in medieval Europe. Originally, the mortgagor gave the mortgagee ownership of the land on the condition that the mortgagee would return it once the mortgagor's debt was paid off. Over time, it became the practice to let the mortgagor remain in possession of the land; it then became the mortgagor's right to remain in possession of the land so long as there was no default on the debt.