HCR diary 5.7.1823 "a Mr Southern whom B: Montague introduced to me and his friend Captain Siborn breakfasted with me" "Southern is a learned - Sib: apparently a very pleasant man"
Marquardt II p 92 26.8.1823 Crabb Robinson met Captain Syborn at Augsburg, Germany
William Siborne (DNB 1797-1849). Not mentioned in DNB article was his part in the Milan Commission, he went to Karlsruhe in connection with Barbara Kress, a witness in the trial of Queen Caroline (Nat Arch TS 11/98, TS 11/113)