W. D. (William Dool) Killen

Born in 1806 in Ballymoney, County Antrim, he became one of the best-known Presbyterian scholars in Ireland. He studied at the Royal Belfast Academical Institution and at the University of Glasgow, and was ordained as a minister in 1829.

He served congregations in Raphoe and later in Belfast, and he also taught ecclesiastical history and pastoral theology at the Presbyterian College, Belfast. Alongside his ministry and teaching, he wrote extensively on church history, with works such as The Ancient Church and The Ecclesiastical History of Ireland helping to establish his reputation as a careful and influential historian.

His career stretched across most of the 19th century, and he remained an important figure in Irish Presbyterian intellectual life until his death in 1902. He is especially remembered for combining the work of preacher, professor, and historian in a way that gave his writing both scholarly depth and a strong sense of purpose.