A more thorough explanation:

Definition: Parliamentum insanum, also known as Mad Parliament, was an assembly of 24 barons summoned to Oxford by King Henry III in 1258. The assembly carried out certain reforms to settle differences between the king and the barons. It was called the Mad Parliament because it abridged the king's power and gave unprecedented powers to the barons. The parliament produced the Provisions of Oxford.

Example: The Mad Parliament of 1258 was a significant event in English history. It marked a turning point in the balance of power between the king and the barons. The Provisions of Oxford, which were produced by the parliament, limited the king's power and established a council of 24 barons to oversee the government. This was a major shift in power from the king to the barons.

Explanation: The example illustrates how the Mad Parliament abridged the king's power and gave unprecedented powers to the barons. The Provisions of Oxford, which were produced by the parliament, limited the king's power and established a council of 24 barons to oversee the government. This was a significant change in the balance of power between the king and the barons, and it had a lasting impact on English history.