Leo II

Unlike the boy emperor Romulus Augustulus, Zeno was not a barbarian puppet.

He was an effective general in his own right, serving as magister militum before he was named as co-emperor and effective regent for his child son, Leo II.

See, Zeno married the daughter of the aging emperor Leo I, and as such, Zeno's son was Leo I's grandson and legitimate heir.

Leo I died when Leo II was only seven, so Leo II crowned his father as co-emperor to assist in running things.

In the last year, his father-in-law and son had both died.

Whether Zeno grieved these losses is unknown, but I think it likely that he did.

Thanks to the unexpected death of his child son, Zeno found himself as sole emperor, but within a few months he had to give up the throne and flee from Constantinople so that he wouldn't be killed.

If I were in Zeno's shoes, I would be pretty depressed.