Zacharias (Zachary) Boyd (c1585-1653) was a descendant of the Ayrshire family, the Boyds of Penkill, but was probably a farmer's son. He was educated in Kilmarnock before proceeding to Glasgow University in 1601 and then St Andrews University, 1603-1607, where he graduated MA. He next attended the Protestant college of Saumur in France. He was offered the college principalship, but he declined the offer. He remained in France for sixteen years, before returning to Scotland due to the growing persecution of Protestants in France.
In 1625 he was appointed minister of the Barony parish in Glasgow and was also closely involved with university affairs until his death in 1653. He was elected both Dean of Faculty and Rector of the University on each of three separate occasions and he was also a member of the General Assembly's commission for the visitation of the university on three separate occasions. Boyd was involved in the religious politics of his time, as well as writing prose and poems. He met Charles I the day after his coronation at Holyrood in 1633 and he wrote a Latin ode for the king's coronation. At that stage he was probably not hostile to the idea of bishops which Charles was keen to impose, but he later became a committed Covenanter and in 1640 he wrote a poem about the Covenanting victory at the 1640 Battle of Newburn.
In 1650 he preached a fiery, critical sermon before Oliver Cromwell in Glasgow Cathedral at a time when the Cromwellian conquest of Scotland was underway. Cromwell responded by inviting him to dinner and subjected him to three hours of prayer after which he and Boyd seemed to be on better terms. On his death in 1653 his last will and testament left £20,000 Scots and all his books and manuscripts to the university. His manuscripts are in Glasgow University Library.