Chakri dynasty at English => English (The Britannica Concise) Of Explained:
Thailand's ruling family. Phraphutthayotfa Chulalok (1737-1809) founded the dynasty and ruled as Rama I (r.1782-1809). He reorganized Siam's defenses to successfully repel numerous Burmese attacks. His descendants have reigned in an unbroken line ever since. Rama III (r.1824-51) increased trade with Europe and negotiated a treaty with the British E. India Co; King Mongkut (Rama IV; r.1851-68) and King Chulalongkorn (Rama V; r.1868-1910) helped modernize the government along Western lines and thereby avoided colonial rule. King Vajiravudh (Rama VI; r.1910-25) instituted social reforms and restored the nation's fiscal autonomy (lost to the West under Rama IV). Bhumibol Adulyadej (Rama IX) has reigned since 1946 as Thailand's ceremonial head of state.