Kham Souk was king of the southern Laotian

Kingdom of Champasak The Kingdom of Champasak (Lao: ຈຳປາສັກ ɕàmpàːsák or Bassac, (1713–1904) was a Lao kingdom under Nokasad, a grandson of King Sourigna Vongsa, the last king of Lan Xang and son-in-law of the Cambodian King Chey Chet ...

from 1863 to 1899. He was preceded by Kham Nay, who reigned from 1856 to 1858, and a period of interregnum from 1858 to 1863.Peter Simms and Sandra Simms,
The Kingdom of Laos: Six Hundred Years of History
' (1999), pg 178.

References

Kings of Champasak 19th-century Laotian people {{Laos-royal-stub