The upper classes in Rome held in low esteem, and even in contempt, the tradesmen and mechanics. This might have been because these people performed for the masses the duties that slaves did for the higher classes, and so all were put on the same footing. These people were, with few exceptions, debarred from serving in the legions and in consequence they became cowardly and likewise at times unruly. Yet the laboring class, as everywhere and in all times, were greatly needed at Rome and did perform a large amount of honest and useful labor. The great commerce carried on needed a large number of sailors and in the ports dock hands and porters and clerks. The city, too, needed a large number in the trades, as, bakers, tailors, shoemakers, potters, carpenters, and various kinds of smiths. There were needed plenty of small shops where the people could procure the things necessary for life and such shops would call for the employment of many people. People of the same trades would naturally associate together and attachments would be formed, so that guilds came into existence at an early date, both from this natural instinct of association and for the protection of their trades. Among the crafts represented in the guilds were weavers, carpenters, dyers, leather-workers, tanners, smiths, porters, and a number of others. They were modeled after the gens or family, with a religious center and a patron deity. They had separate inns for their meetings. They had festive days at which times they went in procession through the streets carrying their emblems and banners. They provided for the funerals of their members, they had their widow's fund, and in other ways they looked after the interests of the ones belonging to the guilds. Rome had an extensive commerce. Traders went along with the soldiers or quickly followed after them to open trade with the conquered provinces. Thus London in 61 A. D., only eighteen years after the conquest, had a large number of Roman merchants among its people. The roads built from Rome into all parts of the world greatly promoted commerce. The traders did not stop with the boundaries of the empire but went out among peoples not under Roman sway. As an instance of this was their going out into the North of Europe to the Baltic for amber and at one time there was quite a trade in this and in other articles. Even before Cæsar's conquest of Gaul, Roman traders had entered it over the St. Bernhard pass and had even gone among the Belgæ. The Mediterranean, the Black Sea, and the Atlantic were full of Roman ships trading with the various provinces and countries. The conquest of Egypt opened up a great trade, not only with that country but through it also with Arabia, Ethiopia and even India.