The susceptibility of isolated island-based populations to acute infections like measles is well documented, most clearly in Fiji and the Faröe Islands. We review the remarkably tragic 1824 journey of King Kamehameha II and Queen Kamamalu of Hawaii to London and the later enormous impact of measles on Hawaii on first arrival in 1848. The young royalty came to seek an audience with King George IV to negotiate an alliance with England. Virtually the entire royal party developed measles within weeks of arrival, 7 to 10 days after visiting the Royal Military Asylum housing hundreds of soldiers' children. Within the month the king (27) and queen (22) succumbed to measles complications. Their bodies were transported to Hawaii by Right Honorable Lord Byron (Captain George Anson, the poet's cousin). Before 1848 measles was unknown in Hawaii. Several epidemics struck Hawaii in late 1848, beginning with measles and pertussis, then diarrhea and influenza. Measles arrived at this time from California, spreading from Hilo, Hawaii, through all the islands; 10% to 33% of the population died. Subsequent measles epidemics occurred in 1861, 1889 to 1890, 1898, and 1936 to 1937, the latter with 205 deaths. The imported epidemics of infections including measles diminished Hawaii's population from approximately 300,000 at Captain Cook's arrival in 1778 to 135,000 in 1820 and 53,900 in 1876. The measles deaths of the king and queen in London in 1824, likely acquired visiting a large children's home, was a harbinger of the devastating impact of measles upon Hawaiians 24 years later with its first arrival to the Sandwich (Hawaiian) Islands.