An Overprotective Daughter
Artemis could be harsh and even cruel, but one of her greatest qualities was her complete and unreserved devotion to her mother. Both she and Apollo recognized the difficulty their mother had had in bringing them into the world, and they respected no one more than her. Throughout the myths Artemis and Apollo joined forces to protect their mother or to seek revenge on those who bothered her.
Filled with jealousy and recognizing that she could not prevent the birth of the divine twins, Hera still wanted to punish Leto. While the twins were away from their mother, Hera filled the Giant Tityus with lust for Leto. Acting on his desires, Tityus tried to rape Leto, but Leto cried out to her children, who rushed to her aid. The two shot their arrows at Tityus and killed him before he could violate their mother. (Some myths say that Apollo wasn't present and that Artemis killed Tityus.)
After his death, Tityus was sent to Tartarus. This Giant was so huge that, when he was secured to the ground, his body covered several acres (between two and nine, depending on the myth). Every day, a pair of vultures tore out his liver and ate it, but it grew back every night.
Niobe Speaks Hastily
Niobe was the wife of Amphion, a son of Zeus. She bore him six daughters and six sons. (Some myths disagree about the number: Some say seven daughters and seven sons or even ten daughters and ten sons.) Niobe was a proud mother, and she made the mistake of bragging about her many children on Leto's feast day. Niobe said that her children were better than the twins of Leto, and that she was superior to Leto because she had twelve children, whereas Leto had only two.
Offended by the audacity of this woman, Leto called upon her children to take revenge. Happy to oblige their mother, the twins killed all of Niobe's children with poisoned arrows. Artemis killed the six daughters, and Apollo killed the six sons. (Some myths say that not all the children were killed; two were spared, one girl and one boy.)
According to the Iliad, the children remained unburied for ten days. Finally, on the eleventh day, the gods buried the slain children. The grief-stricken Niobe wept without ceasing. She fled to Mount Sipylus but found no refuge there. The gods took pity on her and turned her to stone. Even after her transformation, Niobe could not stop crying. On Mount Sipylus, there is a limestone rock formation that resembles a human face; after a rain, water seeps out of the porous rock. This is said to be Niobe, still weeping for her lost children.