As in our Contemporary Law, the most important part of sources from which debts were arising was contracts (contractus) in Roman Law. There were some contract types that were accepted as contractus in terms of ius civile in Roman Law. So as to accept that such contracts were heading towards a certain legal result and these contracts in a limited were bearing debts, along with the fact that the consentaneous declarations of intention of the parties the property had to be given to the other party or the consents had to be declared in accordance with a certain form. So one of contractuses that ius civile approved came into existence and it was accepted there was a debt protected by a case. The other contracts different from contractus’ are known as pactum. It was only possible in the upcoming centuries to accept the fact that the contracts were drawn up by consent in the Roman law. The fact that praetors and emperors bestowed a right of action upon any disputes arising from such contracts had an effect on this process. By doing so, the contracts began to be made by only consensus independently of the form and their numbers got increased. Thanks to those developments, there was not any difference between pactums and contractus. Commodatum was used among friends and neighbours in Roman life where the friendship often required mutual services. Despite of this fact, it did not appear as contractus that was accepted by ius civile. In accordance with the development mentioned above, it was born as a pactum between the parties. It only happened under the auspices of the praetor that a lawsuit was brought for the refund of the thing mentioned in the contract. After the reconciliation of the declaration, the commodity mentioned in the contract had to be given to the other party so that commodatum could be set up. So it was coming under the group of the real contracts (re contrahitur) in terms of its formation. The debtor who got the detention of the property got the opportunity to use the property, which is mostly moveable and expendable gratuitously in accordance with the purpose agreed in the contract. In addition, it entered into the obligation of the full restitution during the agreed period.