English Parliamentarian general and a leader in the Fifth Monarchy (Fifth Monarchy Men) sect (men who believed in the imminent coming of Christ and were willing to rule until he came). He helped to bring about the execution of King Charles I.

In the first phase of the English Civil Wars, Harrison fought in the battles of Edgehill, Marston Moor, and Naseby. When he was elected member of Parliament in 1646, he urged the prosecution of Charles I as “a man of blood.” As a Fifth Monarchy man, he wished to institute a government of “saints” and was an active patron of radical preachers. He commanded the guard that brought Charles I to London for his trial in 1648, became a member of the Council of State in 1651, and fought at Worcester (Sept. 3, 1651). He pressed Oliver Cromwell to dissolve the Rump Parliament and was the leading advocate of the subsequent “Parliament of Saints.” When it collapsed, he refused to acknowledge the Protectorate (because it impeded the divine plan), lost his commission in the army, and was imprisoned several times. At the Restoration he was arrested, tried, and executed.