Sphere of influence: Earth
Famous portraits: A few - mosaics, vase paintings and reliefs
Gaia is the first goddess of the Greeks. She comes from the god Chaos, and she mothered a few children without having a father for them, all by herself (parthenogensis). One of these children was Uranus and with him she got even more children - despite her being able to pull it off herself at first, it would seem. This union brought about, among others, Cronos - the son who would eventually castrate his own father with a sickle his mother gave him. Uranus had done some evil things to their children and Gaia could not forgive him. The son cut his genitals off and Gaia got impregnated with the semen which fell to the earth.
All this according to Hesiod in his Theogony.
Gaia was very much a mother goddess, she was the personified Earth, and a nurturing life-giver. She had numerous children - so many it is hard to keep track of them all - with many different men (and as mentioned, some by herself too). These motherly attributes were also present in depictions of her - like this one.