E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
means kings town; so called in honour of King Stephen, who erected a cross there. (French, roy.)
A Royston horse and Cambridge Master of Arts will give way to no one. A Cambridgeshire proverb. Royston was a village famous for malt, which was sent to London on horseback. These heavyladen beasts never moved out of the way. The Masters of Arts, being the great dons of Cambridge, had the wall conceded to them by the inhabitants out of courtesy.