UMFC minister, was a British citizen, born in the Federal Republic of Mexico, where his father (also William) worked with other Cornish miners. From 1887 to 1896 he was a missionary among the Mende people of Sierra Leone, being General Superintendent from 1893. He built on the pioneering work of Joseph New, about whom he wrote A Captive Missionary in Mendiland (1899). In 1896 he published a paper on the Mende people and was made a Fellow of the Royal Geographical Society. In his last year he wrote Mendiland Memories. He died at Heysham in 1926.
His daughter Edith Ibberson Vivian married the Wesleyan minister,the Rev. Cecil Herberrt Rose MA inLancaster in September 1921.