in 1642, the bhutia established a monarchy headed by the chogyal (; divine king), and opened relations with tibet. by the founding of the bhutia monarchy, tibetan sources considered tibetans (bhutia), lepchas, and limbu to be the "original races of the kingdom." around 1819, the lepchas were still the most numerous population, comprising roughly half of all sikkimese, followed by bhutias (30%) and limbus (20%); sources disagree on whether the bhutias outnumbered the limbu or vice versa, but in any event, the limbu frequently intermarried with the lepcha. throughout the nineteenth century, further groups of tibetans known as "rui-chhung" ("little families") migrated to sikkim under british rule.