A more thorough explanation:

Definition: Senatus consultum ultimum necessitatis is a Latin term used in Roman law to refer to a decree of the senate of the last necessity. This decree was usually issued before the appointment of a leader with absolute power during times of emergency.

Example: In 49 BC, Julius Caesar crossed the Rubicon River with his army, defying the Roman Senate's order to disband his troops. The Senate responded by issuing the senatus consultum ultimum necessitatis, which gave Pompey the Great the power to raise an army and defend the Republic against Caesar's forces.

This example illustrates how the senatus consultum ultimum necessitatis was used to grant extraordinary powers to a leader during a crisis. In this case, Pompey was given the authority to raise an army and defend the Republic against Caesar's forces, which were seen as a threat to the stability of the Roman state.