The origin of societies known as guilds is involved in controversy, but they were common throughout all Europe in the Middle Ages, bearing eloquent testimony to the fortifying power of combination. They afforded mutual protection to their members, frequently making good any loss sustained from an insurance fund to which all were contributory, and devoting other portions of their revenues to feasts, almsgiving, and public works. Guilds are best remembered, however, in the twelfth and thirteenth centuries, as monopolist organisations, and a third of all the towns in England, with the possible exception of London, had their merchant guild, or body of traders and handicraftsmen, engrossing the local commerce to the exclusion of all men without their ranks. The craft guild was a century behind the merchant guild in its rise and development. Its members met together to make rules, by which all who practised a particular calling in the locality were to be directed in all affairs connected with their trade or handicraft. They devoted some of their revenue to religious uses, the members frequently supporting some church or chapel, or providing candles for altar or processional lights. Other local guilds not definitely commercial, but rather social, in character, often called after some saint, were active in the performance of all good works; they clad the poor in their livery, supported churches, colleges of priests and grammar schools, and pensioned decayed and deserving members. At Coventry, in the later fourteenth and earlier fifteenth centuries, guilds rose rapidly, and as rapidly coalesced, or, in the case of those "yeomen" or journeymen fraternities, which served to focus the prevailing industrial discontent, failed to maintain themselves in face of the hostility of other powerful previously existing associations. Two fraternities survived to play a great part in the city's mediæval history, the Corpus Christi guild, founded in 1348, and the better-known society of the Holy Trinity, S. Mary, S. John the Baptist, and S. Catherine, properly a fusion of four different fraternities, founded between 1340 and 1364, and known for brevity's sake as the Trinity guild. [Illustration: MINSTREL GALLERY ST MARY'S HALL] It is possible that it was to the foundation of the merchant guild of S. Mary[145] in 1340, the kindred associations which sprang up around it, and to the gifts of their members in lands and money that the townsfolk owed the purchase of the incorporation charter.[146] It is frequently found that the same man serves in different years as mayor and master of the merchant fraternity.[147]