Legal Definitions - reus promittendi

The term reus promittendi refers to the individual in ancient Roman law who made a formal promise within a specific type of contract known as a "stipulation." In a Roman stipulation, one party (the stipulator) would formally ask a question, and the reus promittendi would provide a formal, binding answer, thereby committing to an obligation. Essentially, this is the person who promises to do something or give something.

Here are a few examples to illustrate this concept:

• Example 1: A Promise to Deliver Goods

  Imagine a Roman merchant named Lucius who wishes to purchase a shipment of fine wine from a vineyard owner, Marcus. Marcus, acting as the stipulator, formally asks Lucius, "Do you promise to deliver one hundred amphorae of Falernian wine to my villa by the next market day?" Lucius formally replies, "I promise."

  In this scenario, Lucius is the reus promittendi because he is the individual making the formal promise to deliver the wine in response to Marcus's question, thereby undertaking a contractual obligation.

• Example 2: A Promise to Repay a Debt

  Consider a young Roman citizen, Gaius, who needs to borrow money from a wealthy patron, Decimus. Decimus, as the stipulator, formally asks Gaius, "Do you promise to repay me 5,000 sesterces by the Kalends of April?" Gaius formally replies, "I promise."

  Here, Gaius is the reus promittendi because he is the person formally promising to repay the loan to Decimus, creating a legally binding debt.

• Example 3: A Promise to Perform a Service

  Suppose a landowner, Julia, wants to hire a skilled craftsman, Quintus, to build a new statue for her garden. Julia, as the stipulator, formally asks Quintus, "Do you promise to sculpt and install the statue of Venus according to the agreed design within three months?" Quintus formally replies, "I promise."

  Quintus is the reus promittendi in this situation because he is making the formal commitment to perform the specific artistic service requested by Julia.