Harvey seems to have comported himself well even in the high position of an elect, for in 1628 he was made Treasurer of the College, an office to which he was re-elected in 1629, so that he must have shown some of the business capacity which was so marked a feature in the other members of his family.
In this year Harvey received the commands of the King to accompany the Duke of Lennox (born in 1612) who was sent to travel abroad. This was the first interval in the monotony of his professional life since Harvey's return to England from Padua. But the times soon became so broken that he never afterwards settled down again into anything like his old habits. He was nearly fifty-two years of age when, in September, 1629, the Lord Secretary Dorchester procured a licence for James Stuart, Duke of Lennox, to travel for three years taking with him Dr. Topham, Dean of Lincoln, John St. Almain, and eight other servants. The Duke, who was advanced to the Dukedom of Richmond by letters patent dated the 8th of August, 1641, afterwards became Lord Great Chamberlain, and held many honourable appointments in the reign of Charles I. Clarendon often mentions him as a young nobleman of the highest principles, and his staunch loyalty to the King is shown by his being one of the four Lords who with Juxon attended their master's funeral at Windsor. He subscribed no less than £40,000 towards the expenses of the war.
Harvey had to make many arrangements before he could leave England. On the 3rd of December, 1629, he collected the seven "Elects" at his house, and, after a sumptuous banquet, he asked their permission to resign his office of Treasurer at the College of Physicians, a request which was immediately granted. On the 21st of January he applied for leave of absence from his post of physician to St. Bartholomew's Hospital, for the Minutes record--
"Curia tent. Sabti xxi die Januarii 1629-30.
"In presence of Sir Robt. Ducy Knight & Barronet, President (and others).
"This day Dr. Harvey Physician to this hospital declares to this court that he is commanded by the Kings most excellent majesty to attend the illustrious Prince the now Duke of Lenox in his travels beyond the seas and therefore desireth this court would allow of [Edmund] Smith, Doctor in Physic for his deputy in performance of the office of physician for the poor of this hospital during his absence. It is thought fit that the Governors of this Hospital shall have further knowledge & satisfaction of the sufficiency of the said Mr. Smith. Then they to make their choice either of him or of some other whom they shall think meet for the execution of the same place during the absence of the said Dr. Harvey."