The term dar al-Ahd (Arabic: house of treaty or house of truce) was invented to describe the Ottoman Empire's relationship with its Christian tributary states. The invention of a new term was necessary, as the worldview prevalent at the time did not allow for a protracted peace with non-Muslim states, even those under Muslim domination. See dar al-Harb, dar al-Islam.

Today, the term refers to those non-Muslim governments which have armistice or peace agreements with Muslim governments. (The actual status of the non-Muslim country in question may vary from acknowledged equality to tributary or puppet state.)