Collection Manuscript/Mixed Material Image 1 of Item 5. Letter from Sultan Ahmad ibn Sultan Zainal Abidin of Terengganu to Colonel William Farquhar. Resident of Singapore. 29 Rejab 1234 (24 May 1819). Item 5. Letter from Sultan Ahmad ibn Sultan Zainal Abidin of Terengganu to Colonel William Farquhar. Resident of Singapore. 29 Rejab 1234 (24 May 1819).