Roman Republic
The last king of the Roman Kingdom, Lucius Tarquinius Superbus, was overthrown in 509 BC by a group of noblemen led by Lucius Junius Brutus. Tarquin made a number of attempts to retake the throne, including the Tarquinian conspiracy, the war with Veii and Tarquinii and finally the war between Rome and Clusium, all of which failed to achieve Tarquin's objectives. The most important constitutional change during the transition from kingdom to republic concerned the chief magistrate. Before the revolution, a king would be elected by the senators for a life term. Now, two consuls were elected by the citizens for an annual term. Each consul would check his colleague, and their limited term in office would open them up to prosecution if they abused the powers of their office. Consular political powers, when exercised conjointly with a consular colleague, were no different from those of the old king.

Q: Who were the joint consulars considered to be an equal of politically?
old king