Hydatius was born around the year 400 in the environs of Civitas Lemica, a Roman town near modern Xinzo de Limia in the Spanish Galician province of Ourense.
In this context, Hydatius took part in a deputation of the year 431 requesting assistance in dealing with the Suevi from the general Flavius Aëtius, the most important representative of the imperial government in the West.
We know very little else about Hydatius's life, though we know he was kidnapped and imprisoned for a time in 460 by local enemies, which suggests he played an important role in the internal politics of Roman Gallaecia.
A consciously Christian genre, the main goal of the chronicle was to place human history in the context of a linear progression from creation according Genesis to the Second Coming of Christ.
He narrates the events from 427 onward as a contemporary witness and the text becomes increasingly full as the years progress until it resembles an organic literary work more than a typical chronicle.
Hydatius's main concern throughout is to show the dissolution of civil society in the western Roman empire and in Hispania in particular, and he paints a very dark picture of fifth-century life.
This is especially true of the narrative climax of his account, the sack in 456 of the Suevi capital at Braga by the Visigothic king Theodoric II, acting in the service of the Roman emperor Avitus.