Emperor or no emperor, you still need to eat your spinach when your mother tells you to. We all know about the lavish dinners these guys enjoyed, with mice dipped in honey, flamingo tongues and stuffed udders, but they still had to get their daily intake of vitamins, right?
And some emperors liked their veggies more than others.
Tiberius, "the gloomiest of men”, as Pliny puts it, was a harsh ruler, but a brilliant general and an effective administrator. Before becoming emperor, he conquered Pannonia, Dalmatia, Raetia and obtained significant victories in Germany, pretty much establishing the Northern border of the Empire for the rest of its existence.
His military victories were based on cucumbers. Tiberius loved cucumbers so much, he couldn't go through a day without them. So, during his military campaigns, his slaves brought along mobile greenhouses, in with cucumbers were planted in layers of prepared soil put in carts, and then covered to protect them against the harsh weather of the North.
Who knows, maybe he would've never made it as Augustus' successor without cucumbers.
Diocletian reorganized the Empire, saving it from total chaos, standardized taxation, stabilized the economy, reduced the inflation, reached record levels of military growth, persecuted the Christians and still found time for his cabbages.
Well, he was a weird one – because he retired, something unthinkable for an Emperor. He took his complimentary gold watch and moved to Dalmatia, where he enjoyed the sun and the sea in his last years, and took up farming as a hobby.
He lived long enough to see his carefully implemented ruling system fall apart, and the Empire torn by civil wars once again. People came to his palace to beg him to return to work – you know, to be emperor'n stuff, to which he replied: "If you could show the cabbage that I planted with my own hands to your emperor, he definitely wouldn't dare suggest that I replace the peace and happiness of this place with the storms of never-satisfied greed."
Some reports suggest that Diocletian committed suicide three years later. Maybe due to a bad crop season.
Caesar was a frugal man, capable of enduring the long and hard military campaigns on the same ratios as his soldiers. One famous image depicts him while giving a motivational speech to his army before invading Gaul, with a half-eaten radish in his hand. Unfortunately, the author forgets to mention whether Caesar actually liked radishes and finished eating it while delivering his speech, or the radish was just a prop for the comic relief.
Others say that both Caesar and his infamous mistress Cleopatra enjoyed pickles. You'd hope they invited their guests to the luxurious palaces in Alexandra to something more than a pickle party.