Hall's initial work of religious controversy was against Protestant separatists. In 1608 he had written a letter of remonstrance to John Robinson and John Smyth. Robinson, who had been a beneficed clergyman near Yarmouth, had replied in "An Answer to a Censorious Epistle"; and Hall published (1610) "A Common Apology against the Brownists", a lengthy treatise answering Robinson paragraph by paragraph. It set a style, tight but rich using animadversion, for Hall's theological writings. Hall criticised Robinson, the future pastor of the "Mayflower" congregation, alongside Richard Bernard and John Murton.