Hera was a goddess of the Ancient Greek pantheon. She was the wife and older sister of Zeus. Her chief function was as goddess of women and marriage. The Romans conflated Hera with their own Queen of the gods Juno.
Hera was known for her jealous and vengeful nature, most notably against Zeus's paramours and offspring, but also against mortals who crossed her.
Hera and Zeus tasked Andromeda with vanquishing the Gorgons, three creatures of entrancing beauty. Zeus indicated his willingness to vanquish them himself, but Hera refused to allow him, knowing he would be too easily entrapped by the Gorgons' beauty.
Hera presented Andromeda with a shield that would distort the reflection of whoever gazed into it to aid her in her task.