The Lollards were disciples of Wyclif, and increased very considerably in numbers and in power at the beginning of the fifteenth century. A large number of the citizens of London appear to have become attached to the new doctrines, which repudiated some of the most important dogmas of the Church. The clergy were active in their efforts to suppress the new beliefs, and applied to the King for assistance. Whatever may have been the personal views of Henry IV. and Henry V. on the matter, they were compelled by force of circumstances to keep on good terms with the Church, and measures of repression were adopted. The leader of the Lollards, Sir John Oldcastle, a man of distinguished military ability, was imprisoned, but rescued from the Tower by a band of Londoners. A huge meeting was held in St. Giles's Fields, but was prevented from doing any damage by Henry V.'s vigilance; the party was vigorously persecuted, and Oldcastle was captured and hanged. After this Lollardry languished, and gradually disappeared. The King to the Mayor and Sheriffs of London: Greeting. Inasmuch as we have been given to understand that certain priests, not privileged by law for this purpose, nor licensed by the diocesan of the place, nor permitted by the Church, who are said to be of this new sect of the Lollards, have been preaching in public places within the aforesaid city, and in the suburbs and vicinity thereof, in order to excite and win over some who are ill disposed to the Catholic faith and the doctrine of holy mother Church; and by their own rashness, and contrary to the laws and ordinances of the Church, they have preached, nay, rather have profaned the Word of God; or at least under pretext of preaching they have in such places been emboldened to propagate discord among our people on the pestiferous seeds of Lollardism and evil doctrine, after the manner of preachers; and as some of our people of our said city and its vicinity, under pretence of hearing such preaching, have assembled to those places, and have congregated together in large multitudes; and, in consequence, murmurs and seditions have in part arisen, and will probably arise, to the disturbance and no small marring of our peace, unless a remedy be more quickly applied to abolish such meetings and pull down such conventicles: We, desiring especially to provide for the defence of the Catholic faith, the laws and ordinances of the Church, and for preserving our peace, command you, that you cause proclamation publicly to be made, within our city aforesaid, and its suburbs, in every place where you shall find it expedient: