In particular, the perpetual league between Rome and Latium declared all contracts between Romans and Latins to be valid in law, and at the same time instituted in their case an accelerated civil process before sworn "recoverers" (-reciperatores-).

As, contrary to Roman usage, which in other instances committed the decision to a single judge, these always sat in plural number and that number uneven, they are probably to be conceived as a court for the cognizance of commercial dealings, composed of arbiters from both nations and an umpire.
They sat in judgment at the place where the contract was entered into, and were obliged to have the process terminated at latest in ten days.

The forms, under which the dealings between Romans and Latins were conducted, were of course the general forms which regulated the mutual dealings of patricians and plebeians; for the -mancipatio- and the -nexum- were originally not at all formal acts, but the significant expression of legal ideas which held a sway at least as extensive as the range of the Latin language.
Dealings with countries strictly foreign were carried on in a different fashion and by means of other forms.

In very early times treaties as to commerce and legal redress must have been entered into with the Caerites and other friendly peoples, and must have formed the basis of the international private law (-ius gentium-), which gradually became developed in Rome alongside of the law of the land.

An indication of the formation of such a law is found in the remarkable -mutuum-, "the exchange" (from -mutare- like -dividuus-)--a form of loan, which was not based like the -nexum- upon a binding declaration of the debtor expressly emitted before witnesses, but upon the mere transit of the money from one hand to another, and which as evidently originated in dealings with foreigners as the -nexum- in business dealings at home.