William Kiffen (1616-1701) is the subject of the 7th essay in The British Particular Baptists, Volume 1, Revised

From the 1640’s till his death at the beginning of the next century, William Kiffen was a source of strength and stability to the Calvinistic Baptist movement and played a vital role in its growth and advance. It was during his years of leadership of the movement that those positions distinctive of the Calvinistic Baptists were hammered out—congregational church government, believer’s baptism and a strong commitment to evangelical Calvinism. Kiffen thus had no small part in the determination of the future identity of this Christian tradition. --Michael A. G. Haykin