Knox's work in the castle and town of St. Andrews was interrupted by the arrival of a French fleet (July 1547), which battered the walls with artillery until the castle was compelled to surrender. He and all the inmates were carried over to France. They had secured as terms of surrender that their lives should be spared; that they should be safely transported to France; and that if they could not accept the terms there offered to them by the French King, they should be allowed to depart to any country they might select for their sojourn, save Scotland. It was not the custom, however, for French kings to keep promises made to heretics, and Knox and his companions were made galley-slaves. For nineteen months he had to endure this living death, which for long drawn out torture can only be compared with what the Christians of the earliest centuries had to suffer when they were condemned to the mines. He had to sit chained with four or six others to the rowing benches, which were set at right angles to the side of the ship, without change of posture by day, and compelled to sleep, still chained, under the benches by night; exposed to the elements day and night alike; enduring the lash of the overseer, who paced up and down the gangway which ran between the two lines of benches; feeding on the insufficient meals of coarse biscuit and porridge of oil and beans; chained along with the vilest malefactors. The French Papists had invented this method of treating all who differed from them in religious matters. It could scarcely make Knox the more tolerant of French policy or of the French religion. He seldom refers to this terrible experience. He dismisses it with: "How long I continewed prisoneir, what torment I susteaned in the galaies, and what war the sobbes of my harte, is now no time to receat: This onlie I can nocht conceall, which mo than one have hard me say, when the body was far absent from Scotland, that my assured houp was, in oppin audience, to preache in Sanctandrois befoir I depairted this lyeff."[290]