In Mary Shelley's Frankenstein, who was the "Modern Prometheus?"

Although more commonly know by the first half, the full
title of Mary Shelley's novel is: Frankenstein or The Modern Prometheus.  Both parts of
this title refer to the main character, Victor Frankenstein.  It is important to note
that his creation, the monster, is unnamed.

In order to
understand the comparison being made in the title, we need to look at Prometheus in
Greek mythology.  Prometheus was one of the Titans, who existed before the Greek
Pantheon of gods.  He is given credit for creating human beings from clay, water, and
divine breath.  In trying to advocate for humans, Prometheus inadvertently angers Zeus
who punishes humanity with misery and illness.  Finally Prometheus is sentenced to an
eternity of torture for bringing fire (which represents enlightenment and knowledge) to
his creatures.

From this description, there is a clear
comparision between Prometheus and Victor Frankenstein.  Both sucessfully created human
life and faced results not in line with their expectations.  In an attempt to help their
creations, both Prometheus and Victor Frankenstein caused more damage and disorder. 
This eventually led to the harm of both, either through death or eternal
torture.