This is the 12289th most frequent Russian word.
историей
The Russian word "историей" is the instrumental case of "история," meaning "history" or "story."
In this sentence, 'историей' is used in the instrumental case to indicate the field of study or area of interest, in this case, 'the history of art.'
Она увлекалась историей искусства.
She was fascinated by the history of art.
Here, 'историей' represents a specific narrative or tale, used in the instrumental case to express the means of sharing an interesting story.
Вчера он поделился интересной историей.
Yesterday he shared an interesting story.
In this example, 'историей' refers to the background or development of a project, again in the instrumental case to show engagement or work upon something.