In 1817 John Williams and his wife voyaged to the Society Islands, a group of islands that included Tahiti, accompanied by William Ellis and his wife. John Williams and his wife established their first missionary post on the island of Raiatea. From there, they visited a number of the Polynesian island chains, sometimes with Mr & Mrs Ellis and other London Missionary Society representatives. Landing on Aitutaki in 1821 they used Tahitian converts to carry their message to the Cook Islanders. One island in this group, Rarotonga (said to have been discovered by the Williamses) rises out of the sea as jungle-covered mountains of orange soil ringed by coral reef and turquoise lagoon and Williams became fascinated by it. The Williams' became the first missionary family to visit Samoa.
The Williamses returned to Britain in 1834 where John supervised the printing of his translation of the New Testament into the Rarotongan language. They brought back a native of Samoa, named 'Leota' who came to live as a Christian in London. At the end of his days Leota was buried in Abney Park Cemetery with a dignified headstone paid for by the London Missionary Society, recording his adventure from the South Seas island of his birth. Whilst back in London, John Williams published a "Narrative of Missionary Enterprises in the South Sea Islands", making a contribution to English understanding and popularity of the region, before returning to the Polynesian islands in 1837. Most of the Williams' missionary work, and their delivery of a cultural message, was very successful and they became famed in Congregational circles. However, whilst visiting a part of the New Hebrides in November 1839 where John Williams was unknown, he, along with fellow missionary James Harris, was killed and eaten by cannibals on the island of Erromango during an attempt to convey to them the blessings he brought. A memorial stone was erected on the island of Rarotonga in 1839 and is still there today. Mrs Williams is buried with their son (Samuel Tamatoa Williams, who was born in the New Hebrides) at the old Cedar Circle in London's Abney Park Cemetery; the name of her husband and the sad record of his death, was placed on the most prominent side of the stone monument for all to remember.