Wyllie was born October 13, 1798, in an area called Hazelbank in Dunlop parish of East Ayrshire, Scotland.

He took a small yacht, Daule, to Kolkata, India (then called Calcutta), from 1824 to 1826, stopping in the Hawaiian Islands en route.

A friend William Edward Petty Hartnell had settled near Monterey, California since 1822, taking the name Don Guillermo and a Spanish wife.

Writing about this episode, a historian says:...no drama in the Pacific was complete without the fastidious, meticulous and verbose Scots busybody, Dr. Robert Chrichton Wyllie.

[6]: 83 He stayed with British Consul to Mexico (and fellow Scot) Alexander Forbes, hoping to get help from his investors for the California scheme.

[6] By the time McNamara acted, however, events such as the "Bear Flag Revolt" gave the United States effective control over California.

Miller had just been appointed British Consul to the Kingdom of Hawaii and convinced Wyllie to come with him while he was waiting for a response from his investors.

He was then appointed by King Kamehameha III as Minister of Foreign Affairs, Secretary of War, and to the legislature in the House of Nobles on March 26, 1845.

[7] He was seen as a counter to the American influence of Gerrit P. Judd, who had been a missionary doctor before becoming the first Treasurer, effectively the most powerful position in the country.

[8] One of his first assignments was to list the various complaints between the previous British Consul Richard Charlton and the American Commissioner George Brown.

Former Hawaiian newspaper publisher James Jackson Jarves negotiated a treaty with John M. Clayton signed on December 20, 1849.

Eames had been appointed by President James Polk for this purpose, but got only as far as San Francisco when he got involved in the California Gold Rush.

Wyllie had suggested dismantling the old Honolulu Fort, since its outdated armaments had proven to be useless in preventing attacks anyway.

[15]: 69 Brannan's men destroyed some mail on their ship, hoping to start a surprise rebellion, but Wyllie had already heard rumors and had them closely watched.

By the end of 1853, foreign residents were pressuring the king to sign a treaty of annexation with the United States to protect them from more rumored insurrections.

A letter once appeared in the Ayr Advertiser confusing Wyllie with English physician Thomas Charles Byde Rooke, who was adoptive father of Kamehameha IV's wife Queen Emma.

[23] Wyllie kept Hawaii officially neutral during the American Civil War,[24] but promoted continuing trade of sugar and other products to the expanding Californian market.

[25] In 1859, Wyllie instructed the Hawaiian Consul in London, Manley Hopkins[26] to send a priest from the Anglican church.

He also contacted William Ingraham Kip of the American Episcopal Church in California who supported the idea, but the Civil War prevented any help from them.

[27] Wyllie encouraged Emma to write to Queen Victoria, and despite the contrast in their respective dominions, they became lifelong friends.

He insisted on formal European-style military uniforms for both royalty and cabinet officers, and favored decorative medals such as the Royal Order of Kamehameha I.