Robert Heath left St John's without taking his degree, to become a lawyer. A protégé of George Villiers, later Duke of Buckingham, Heath became recorder for the corporation of London in 1618, soliciter-general in 1621 and attorney-general in 1625. He was also MP for East Grinstead in the parliaments of 1624-5. After Buckingham's assasination in 1628 his career went into decline. He was made a judge in the Court of Common Pleas in 1631, but was dismissed in 1634, possibly due to the machinations of William Laud. In 1637 he was appointed a king's serjeant, and in 1640 he returned to the bench. After the outbreak of the civil war he became an exile in France, and died at Calais in 1649. During his life he was involved in administering the colonization of North America, and invested in many speculative ventures, including Vermuyden's schemes for draining the fens.
With most of his wealth invested in speculations or divided among his family, Heath left only a small bequest to St John's. He gave around eight volumes to the Library to the value of £20, all on the deliberations of Church councils, printed in the 1620s.
All the volumes given by Heath bear an armorial binding-stamp, together with a book label. In translation this reads:
A small gift from the grateful memory of Robert Heath, knight, Attorney General to the most illustrious Prince Charles: of this College once an alumnus.