[1] He continued his professional life as surgeon to the forces sent under Ambrose Dudley, 3rd Earl of Warwick in 1563 to relieve Le Havre.
The military expedition to the Low Countries under Robert Dudley, 1st Earl of Leicester in 1585 gave Banister another opportunity of public service, and he served on board a ship.
Complaints were often made at that time to the College of Physicians as to surgeons practising medicine, and, perhaps in consequence of some such difficulty, Banister in 1593 obtained a royal letter of recommendation which led the college to grant him a license (15 February 1594) on the condition that in dangerous cases he should call in one of its fellows.
He had a long epitaph in English verse, which bears sufficient resemblance to some poems of Clowes to make it likely that it was written for Banister's tomb by his old friend.
He compiled a collection of remedies and prescriptions, 'An Antidotarie Chyrurgicall,’ London, 1589, in which he acknowledges the generous help of his contemporaries, George Baker, Robert Balthrop, Clowes, and Goodrus.