when entering into a legal agreement, it is not unusual for one of the parties to ask the other to provide some security so as to ensure that the latter's obligations under the agreement will be fulfilled. There are two basic forms of security, personal and real. In personal security for a loan, the borrower arranges for a third party to come forward and to promise the lender that he will fulfill the borrower's obligations in the event that the borrower does not make interest payments or repay the principal. In real security, the borrower pledges some of his property, either movable or immovable, as security to the creditor. If the borrower defaults, the creditor has the right to seize the property pledged as security and, if he wishes, to sell it for cash in lieu of repayment.

During the Classical and Hellenistic periods, the Athenians used both personal and real security in their legal agreements. Real security appears to have been used primarily in three types of agreements: loans, dowries, and leases. Our information about the use of real security at this time comes from two main sources: one literary, the other epigraphical. First, there are the speeches of the Attic orators written for delivery in private suits. Second, there are the many Attic inscriptions that deal with financial matters, especially the horoi. The horoi are flat slabs of stone that were placed on properties that had been pledged as security. The purpose of the horoi was to warn third parties that there was a lien on the property.