Abstract: A copy of a letter from Henry Willock, HM Chargé d’Affaires in Persia [Iran], to Major-General William Grant Keir, Commander of the 1819 expedition to the Persian Gulf, sent from Tehran and dated 16 March 1820. The letter reports the Persian Court’s muted reaction to the destruction of ‘pirate’ vessels from Lingua [Bandar-e Lengeh] and Charrack [Bandar-e Chārak], asserting that Grant should continue in his mission against ‘piracy’ originating from Persian ports.The letter was enclosed in Willock’s letter to the Secret Committee of the Court of Directors of the East India Company dated 19 March 1820 [IOR/L/PS/9/69/10].Physical description: Condition: the letter was perforated in an attempt to stop the spread of disease.