A third function became attached to the posts, viz. the transmission of private letters. As it is impossible to say at what date the posts began to be used by ordinary travellers, so it is impossible to say at what date they were first used for the conveyance of letters other than those on the affairs of the King or of the State. The universities and municipalities provided services for the carriage of their own letters;[19] but from a very early period the posts were also made use of for the conveyance of unofficial letters. The Master of the Posts received no direct profit from the carrying of such letters,[20] but the price paid to him for the office of Deputy Postmaster was probably thereby increased.[21] A Proclamation of 26th April 1591 prohibited the conveyance of letters to or from countries beyond the seas by any person other than the ordinary posts and messengers; and referred to previous similar prohibitions. The object of this prohibition, which foreshadowed the monopoly of the carriage of all letters, whether for places within the realm or to or from foreign countries, was alleged to be the redress of disorders among the posts in general, and particularly to prevent inconveniences both to the royal service and the lawful trade of honest merchants.[22] A Proclamation of 1609 repeated this prohibition.[23] In 1626 a legal struggle was in progress between Matthew de Quester and Lord Stanhope, both of whom claimed to hold a King's Patent conferring the right to carry foreign letters.[24] This litigation led to laxity and omission in the conduct of the foreign service, so that merchants trading abroad were put to great inconvenience. In consequence, in November of that year, the King granted the Merchant Companies permission to arrange for the conveyance of their foreign letters by their own messengers. The high authorities were disturbed by the grant of this permission,[25] and in October 1627 it was revoked "upon weightie reasons of State." Only the Merchant Adventurers were still permitted to use their own messengers, and they and all other merchants were required in times of war and danger to the State to acquaint the Secretaries of State from time to time with what letters they forwarded abroad.