While not an exact parallel, there are some similarities with the story of the 11th century BCE Duke of Zhou.

Dan, the Duke of Zhou, was the younger brother of King Wu. King Wu died only a few years after attaining power, and his son Cheng, the heir apparent, was still young. By that time the Duke of Zhou (who was also Cheng's uncle) had proven himself capable of maneuvering the political landscape of the era, and he became regent for the young now-King Cheng, claiming that having such a young ruler would be dangerous for a dynasty still facing so much opposition. Being an influential family member of a recently-established dynasty, the Duke of Zhou faced suspicion, rebellion, and revolt from both sides: members of the deposed Shang dynasty wanted to be back in power, and other members of the Zhou dynasty feared he was going to claim the throne for himself.

The now-regent Duke exceeded all expectations: not only did he survive an outright civil war during his administration, but he was utterly committed and loyal in his role as a both a regent and a tutor to Cheng. Most critically, after seven years, the Duke of Zhou willingly stepped aside and let his nephew take the throne. He didn't -- and probably couldn't -- slip into obscurity after that, but taking orders from the emperor he tutored was certainly a step down from trying to become emperor himself.

That's where the similarities start to fall apart. While Cincinnatus returned to obscurity, The Duke of Zhou is a full-on culture hero, attributed with everything from writing the I Ching to creating Chinese court music to having the power to appear in people's dreams.