In the years which immediately followed the Conquest the more important towns of England suffered greatly, partly on account of the chances of war and partly on account of the policy of castle-building associated with the English kings of the Norman period. However, as soon as the Norman rule was firmly established, an internal peace, such as had not been previously enjoyed, was secured for this country; the towns, consequently, made rapid progress, and in one commercial centre after another a gild-merchant was set up.[424] A gild-merchant came into existence for reasons similar to those which brought into being the religious and social gilds. There was a consciousness of a community of interest, and a common object which could be secured more effectively through co-operation. It is foreign to our purpose to attempt to examine critically the origin of gilds-merchant, and so it must suffice for us simply to state that their history has been traced back to corporations of merchants and artisans, which existed in Rome under Numa Pompilius, and which were termed "collegia" or "corpora opificum et artificium."[425] In France, the first gild-merchant was formed in 1070, and came into existence for the purpose of protecting the free townsmen against the oppression of the nobility. Gradually their number increased, and with the growth in their number their purposes became more clearly defined, and the custom developed that the gild should receive formal recognition from recognised authority. Thus the traders of Paris formed the "Hanse des marchandes de L'eau" and the privileges they claimed were confirmed by Louis VII. in 1170.