Nautical loan (fenus nauticum or pecunia traiecticia) is a special institute of the Roman law. It is almost certain that this institute has been incorporated in Roman law from the Ancient Greek legal system. Even so, it could be said that the very origins of this institute could be found in other ancient countries (Babylonia, India, Phoenicia and Greece). Fenus nauticum is the institute of Roman private law where the creditor gives money, which has to be transported across the sea or where creditor invests money in buying goods that will be transported over the sea. Creditor bears the risk of all possible accidents that could appear in the nautical transport (and that includes any kind of risks) for money or goods. The loan will be refunded only in cases where the ship or cargo safely arrives at the destination. This loan had the function of nautical insurance. The premium is paid in the form of interest (usurae maritime), which are always, because of the risks, were greater than usual interest and in the classical law they were unlimited. Iustinian has been the only one that limited those interests at rate of 12%. For contracting those interests plain pact (nudum pactum) has been sufficient. Nautical loan played a significant role in the trading, which has been extremely developed in certain period of Roman state. As an institute that provides the possibility of large profits but at the same time wearing a high risk, it has been very attractive to Roman aristocrats. However, providing these types of loans wasn't only the business of wealthy aristocrats, but also the business of professionals who has been specialized for dealing with fenus nauticum. With the decline of trade and the collapse of the Roman Empire, the role of the institute has been reduced. Reoccurrence of nautical loan happened in the XII century. Then, as in the ancient laws, it played a significant role in overseas trade. In fact, during this period there was a revival of Italian cities, the development of trade, but also a renewal of interest for studying the rules of Roman law. Nautical loan served not only in overseas trading ventures but also in the inland trading (fenus quasi nauticum). The importance of this institute could also been seen in one if the decisions of Gregor IX (Naviganti veleunti), which, although not entirely clear, in the opinion of the majority, allows interests in nautical loans. Canonists have also allowed interests in nautical loans because of the risks for the participants. Even so, many of them took a stand that this is not a loan because a high risk rate involved makes the very nature of this institute completely different. Those claims could be supported with arguments. Still there are different opinions of fenus nauticum's legal nature, where some claims that this is kind of loan, the others thinks that this is type of the insurance contract, and there are those who stands on the point that this is a special unnamed contract.