Hera (Romanized as Juno).
She is the long suffering wife (and sister – this is the Egyptian influence on Greek mythology, where the Pharaoh married his sister to ‘keep the bloodlines pure’) who is the goddess of marriage, hearth (family home) and protector of women (especially during childbirth).
When Ancient Greeks conquered a people, they integrated their main god into Zeus, claiming they were really one and the same and making the cultural/social integration of the conquered peoples that much more possible.
‘Integrating’ the ‘queen consort’ was much more difficult.
The way that Ancient Greeks integrated their ‘head god’ Zeus into being just another interpretation of the conquered peoples’ ‘head god’ in order to harmonize the conquered people’s mythology with the Greek one – well, it dealt a rather raw deal to the ‘head queen’ of the conquered people’s pantheon: the ‘head god’, Zeus, had a queen (Hera), so, who or what was this other queen goddess of the conquered peoples’ pantheon?
She became Zeus’s mistress.
They all did… and Hera ‘had to’ deal with it, within the constrains of the Ancient Greek Mythology – which she did, in epic Hera way, as has been recorded in myth of how she had treated Hercules.
Xanthippa's Chamberpot 