In Greek mythology Cronus aka Kronos (Saturn to the Romans) was the leader god. He was, for a long time, confused with Chronos. Therefore, he was portrayed with a scythe.

Time Showing the Ruins that He Causes and the Works of Art He Brings to Light by
Jean-Baptiste Mauzaisse. 1822.

The oracle predicted to him that his son would unseat him for the position of the supreme god.
Cronus did not want to use condoms (latex allergy) and refused cut the sperm ducts (afraid of surgeons). The female hormonal contraceptives were not invented at that time. So he slept unsafely with his wife, she was constantly pregnant and was giving birth to children.

To evade his fate Cronus decided, for some reason, that to get rid of his children it would be very effective to swallow them.
Despite the fact that the oracle warned about boys only, Cronus devoured newborn girls too, which shows that he was the first to support women’s equality in public policy.

Francisco de Goya Art
Saturn Devouring his Son by Francisco de Goya. 1819-1823.

When his wife gave birth to a child for the 6th time (Zeus, mind you), she suddenly realised that she did not like the behaviour of her husband. It was ok before that. Her husband would just protect her in this way, taking care, depriving her of postpartum depression, lack of sleep because of breastfeeding and other insanity.
But now for some reason she decided that it should be different.
Must be besties to work her up into a state like this.

Saturn Devouring His Son by Peter Paul Rubens. 1636.

She left the newborn Zeus in a baby box on the island of Crete, and gave her husband a stone wrapped in nappies, which he swallowed trustingly.
(By the way this proves that the artists who illustrated this story were overdoing with bloodthirstiness. Cronus obviously did not chew the babies, but swallowed them whole, otherwise he would break his teeth with this stone).

R16.1Kronos.jpg
Rhea gives Cronus a stone wrapped in diapers. Roman relief.

When Zeus grew up he found his mother using the biological parents search site. Together they decided to take revenge on the voracious daddy. Using a fake record of employment and fake birth certificate, the young man got a job as a waiter at his father’s ski residence in Olympus (2,917 meters above sea level).

Cronus devouring his children. French miniature. 15th century.

One day Cronus asked for some wine. Zeus gave him a drink, mixed in mustard and salt (must be some godlike recipe in case of poisoning – write it down). Cronus has drank it, got sick and spewed out of his belly his children gently kept there — Hestia (the goddess of the hearth), Demeter (harvest), Hera (marriage & birth), Hades (underworld) and Poseidon (ocean). Since Cronus was the god of time looks like a unique temperature and temporal balance happened in the stomach, which allowed them to survive perfectly and even grow up (since they immediately began to help Zeus in his fight with the titans).

File:Saturn devouring his Son by Giambattista Tiepolo.jpg
Saturn devouring his Son by Giambattista Tiepolo. 1745.
Cronus Devouring His Children by Pietro Muttoni.

Zeus became the supreme god indeed and Cronus retired on pension. Everything came out very humanely: one generation earlier Cronus took this position having castrated his father Uranus by the sickle. This time the emetic was enough. But it is not so aesthetically pleasing, of course. 

The Mutilation of Uranus by Giorgio Vasari. 16th century.