The Chargé d'Affaires (French for "person charged with business") is an international diplomatic concept referring to a diplomat who serves as the chief of mission for an embassy. The term emerged in the latter half of the 18th century, with the French phrase chargé d'affaires appearing around 1767. It was created to provide a less expensive and less politically charged way to maintain diplomatic relations, avoiding the high costs and "battles of prestige" associated with exchanging ambassadors.
The function is primarily governed by the Vienna Convention on Diplomatic Relations (VCDR) of 1961. The most common type is the Chargé d'Affaires ad interim (CDA a.i.), who acts provisionally as the head of mission when the accredited ambassador is absent, incapacitated, or the post is vacant. This mechanism is codified in Article 19(1) of the VCDR. The CDA a.i.'s authority is established by a notification to the receiving state's foreign ministry, known as a "Note of Assumption of Charge," and does not require presenting letters of credence to the head of state.
The concept connects directly to the hierarchy of diplomatic agents, as the VCDR recognizes the Chargé d'Affaires en pied (or en titre) as the lowest of the four classes of heads of mission under Article 14. Unlike an ambassador, who is accredited to the host's head of state, a Chargé d'Affaires en pied is accredited from one foreign minister to another. While a Chargé d'Affaires enjoys the same diplomatic privileges and immunities as an ambassador, the position is often used to signal "cooler ties" or non-recognition of a regime, or during the transition period between ambassadorial appointments. The core provisions of the VCDR of 1961 regarding this role have remained the same, with the distinction between the temporary ad interim and the permanent, lower-rank en pied continuing to be the key feature.