Chao (Thai: เจ้า) is a title of the Lan Na royal family members.
Chao Har Kan (เจ้าห้าขัน, lit.
'five lords') is the style for high-ranking royalty in each Lan Na state.
After the fall of the absolute monarchy, the Chao har kan system was abolished by the People's Party (Khana Ratsadon - คณะราษฎร).
Today, all of the Chao family use na Chiangmai, na Lamphun, and na Lampang as their surname.