Life for the lowest class in ancient Pompeii? It was horrible.

Archaeologists excavating parts of the ancient city of Pompeii made new discoveries Friday that offer a grim glimpse into the bleak existence of enslaved people two millennia ago, including the existence of a “bakery prison.”

The newly excavated area consists of a cramped space where donkeys and enslaved people lived, slept and worked together, grinding flour to make bread. The only window found there provided dim light: it did not give access to the outside world, but to another room in the house, and was crossed with iron bars.

The brutality of working conditions in the factories of that time is graphically described in Book XI of “The Golden Donkey” by second-century author Apuleius, the archaeological site mentioned in a statement issued Friday.

With their feet chained and dressed in rags, Apuleius describes that the workers “had eyes so dull from the scorching heat of that smoke-filled darkness that they could scarcely see, and like wrestlers who were sprinkled with dust before a fight, they became coarse made white with floral ash.”

The donkeys were no better off: ‘Their flanks had been cut to the bone by the brutal flogging, their hooves had been deformed to strange dimensions by the repeated circling, and all their skin was smeared with scabies and hollowed out by hunger.’

Pompeii, buried by an eruption of Mount Vesuvius in 79 AD. current.

Since excavations began in the 18th century, Pompeii has continued to provide valuable insights into the lives and customs of its ancient inhabitants.

The iron bars on the bakery’s window were designed to prevent the enslaved workers from fleeing, Gabriel Zuchtriegel, director of the Archaeological Park of Pompeii, said in a telephone interview.

The limited workspace contained at least four tightly packed millstones. The floor around it is marked by a series of semi-circular indentations of varying depths, to prevent the animals from sliding across the sidewalk, but also to “keep them in a kind of choreography,” Mr. Zuchtriegel said.

“The space was so small that two donkeys couldn’t pass at the same time, so they always had to be careful to stay in sync with the others in some way, and this apparently helped.” They moved around the small space, he added.

Under Mr. Zuchtriegel’s supervision, visitors have received a more complex, interdisciplinary reading of the ancient city, as recent research has focused on the complex stratification of Pompeii’s society, including the lowest classes, to which the majority of its citizens belonged.

The discoveries at the Pompeii bakery offered “a very harsh and grim picture” of life there, Mr. Zuchtriegel said.

The bakery was created during the excavation of a larger home that has already provided some surprises, including a fresco that appears to show a doughy mixture that looks strikingly similar to a pizza. The bakery is behind the wall with the fresco.

In another room – where the lararium, or house shrine, was located – an excavation earlier this year uncovered a series of political inscriptions, the ancient equivalent of today’s election manifestos and posters. The inscriptions invite people to vote for Aulus Rustius Verus, a candidate for the position of aedile, an elected official during the Roman Republic. Mr. Zuchtriegel said the home likely belonged to a supporter of the candidate, possibly one of his freedmen.

For researchers, the discovery of political slogans in the house was a first for Pompeii, said Chiara Scappaticcio, a Latin professor at the University of Naples Federico II, and it suggested the possible collusion between elected officials and the bakery owners.

The current excavation campaign aims to secure and consolidate the slopes along one edge of the unexcavated areas of the ancient city.

The excavations suggest that the house was in the middle of renovation when the eruption of Mount Vesuvius occurred, and that the bakery was probably not in use at the time.