From parliaments and sieges, from Jew and castellan, it is time to turn back to the humbler annals of the town itself. The first event that lifts it into historic prominence is its league with London. The "bargemen" of the borough seem to have already existed before the Conquest, and to have been closely united from the first with the more powerful guild, the "boatmen" or "merchants" of the capital. In both cases it is probable that the bodies bearing this name represented what in later language was known as the merchant guild of the town; the original association, that is, of its principal traders for purposes of mutual protection, of commerce, and of self-government. Royal recognition enables us to trace the merchant guild of Oxford from the time of Henry I.; even then indeed lands, islands, pastures already belonged to it, and amongst them the same "Port-meadow" or "Town-mead" so familiar to Oxford men pulling lazily on a summer's noon to Godstow, and which still remains the property of the freemen of the town. The connection between the two cities and their guilds was primarily one of traffic. Prior even to the Conquest, "in the time of King Eadward and Abbot Ordric," the channel of the river running beneath the walls of the Abbey of Abingdon became so blocked up "that boats could scarce pass as far as Oxford." It was at the joint prayer of the burgesses of London and Oxford that the abbot dug a new channel through the meadow to the south of his church, the two cities engaging that each barge should pay a toll of a hundred herrings on its passage during Lent. But the union soon took a constitutional form. The earliest charter of the capital which remains in detail is that of Henry I., and from the charter of his grandson we find a similar date assigned to the liberties of Oxford. The customs and exemptions of its burghers are granted by Henry II., "as ever they enjoyed them in the time of King Henry my grandfather, and in like manner as my citizens of London hold them." This identity of municipal privileges is of course common to many other boroughs, for the charter of London became the model for half the charters of the kingdom; what is peculiar to Oxford is the federal bond which in Henry II.'s time already linked the two cities together. In case of any doubt or contest about judgment in their own court the burgesses of Oxford were empowered to refer the matter to the decision of London, "and whatever the citizens of London shall adjudge in such cases shall be deemed right." The judicial usages, the municipal rights of each city were assimilated by Henry's charter. "Of whatever matter they shall be put in plea, they shall deraign themselves according to the law and customs of the city of London and not otherwise, because they and the citizens of London are of one and the same custom, law, and liberty."