Marcus Claudius Marcellus/ was the nephew of emperor Augustus. He was born in 42 BCE and he was the son of Gaius Claudius Marcellus and Octavia the Yougher, the older sister of Augustus. Being one of the closest relatives of emperor, he became eventual successor.
From 30 BCE August began to introduce Marcellus into public activity, letting him know that he sees him as future heir. Earlier at the age of three Marcellus he was engaged to Pompeia, the daughter of Sextus Pompey, when the triumvirs Octavian and Marc Antony made peace with him in Puteoli. When Pompey was defeated three years later, Pompeia and her father fled to Asia and the marriage did not take place.
In 29 BCE Marcellus participated in the triple triumph of Octavian, similar to the participation of Octavian in the triumph of Caesar in 46 BCE. In 25 BCE he married a 14-year-old Julia, the only daughter of emperor Augustus. The active promotion of the nephew was proof that Octavian see him as potential successor (the emperor had no male offspring). He carefully guided his political career. The young man became a military tribune, aedile and pontiff, which were to help him adapt to the future control of the Empire.
Unexpectedly, Marcellus fell ill and died in Baiae in 23 BCE. As often happens in such unexpected situations, there were voices about the assassination. There were rumors that Livia had poisoned Marcellus. This version of events was supported by the boy’s mother, Octavia. Most likely, however, the reason for the death was natural. Marcellus became ill with an infection of the upper respiratory tract, which was unskilfully tried to heal. Hydrotherapy (cold baths) was fashionable at that time, which only accelerated the development of the disease and led to death. Octavian, despite his family tragedy, kept searching for his successor.