Artemidorus was born in Ephesus but took the name Daldianus, of Daldis, from his mother's home city in Lydia, in Roman Asia Minor, out of what he described in his own text as respect for its patron deity Apollo Mystes; he is conventionally dated to the second century CE on the basis of internal and contextual evidence rather than any external biographical record. He worked as a professional oneiromantis, a dream interpreter, describing in his own introduction how he collected material for years by consulting practicing diviners across Greece, Italy and Asia Minor and recording the dreams and outcomes ordinary clients reported to them.
That claimed grounding in collected case material, rather than purely inherited literary or philosophical dream theory, is what Artemidorus himself presented as distinguishing his work from earlier writers on dreams, and it gives his surviving text an unusually practical, catalog like character. Little else of his personal biography survives beyond what can be inferred from his own writing, a common situation for technical writers of the period whose public identity rests almost entirely on a single influential text.
His explicit statement of method, that he consulted working diviners in the marketplace rather than relying solely on earlier written authorities, is itself a notable claim for a technical writer of his period to make, positioning collected practical experience above inherited literary tradition in a way many of his ancient contemporaries writing on comparable subjects did not.