Eight years later, in 1883, faced with a renewed Haw threat to his capital at Luang Prabang, Chao Unkham again appealed to Bangkok for assistance.
McCarthy had begun his acquaintance with the Lao-Tonkin borderlands in the 1884, when he led a Thai surveying expedition to Phuan and the southern frontiers of Huaphan, as part of his task of mapping the Thai Kingdom.