In the Roman republic the the wealthy and landed gentry were appointed to the Senate for life and had the real power.
The Roman Republic was an era of classical Roman Civilization that dated back to 509 BC, until 27 BC, with the establishment of the Roman Empire.
The Roman Republic had three different parts to its government: The Senate, The Consuls and The Assemblies.
Even though the other entities had power over trials, laws, war, elections, and so on, the Senate had control over money, administration and details of foreign policy, it had more control over day-to-day life of Romans, which may be considered the most important power, or even Real Power, as stated in the question.