After Artemis left her birth island, Delos, she went to Ambracia, where she saw unhappy people living in terror under the rule of the tyrant Phalaexis. Angry, Artemis sent a lioness to the king to devour him. Once the tyrant was dead, Artemis set the people of Ambracia free and reinstated democracy.
The two giants, sons of Poseidon, Otus and Ehialtes tried to sleep with Artemis to gain access to Olympus. Artemis led them both on to believing that she would sleep with them and made them follow her all the way to the island of Naxos where she disappeared; a beautiful white deer appeared in her place. When the two giants tried to catch the deer from two opposite sides, the deer vanished and the two arrogant giants fell hard onto each other, stabbing one another with their lances.
Niobe, a mortal woman, was the daughter of Tantalus and had seven children, the Niobids. Since Niobe was extremely proud of how beautiful and skillful her sons and daughters were, she acted very arrogantly; she often compared herself to Leto who had only two children, Artemis and Apollo, claiming that she was better than Leto. When Leto found out about this, she asked her son and daughter to go and deal with the problem. The two siblings went to find Niobe and her children and killed them all using their arrows. As Niobe was mourning her seven dead children, Leto was bragging about hers.
Artemis is said to have helped the Greek Megarans when they were fighting against the Persians during the famous Persian war. After praying to her for help and protection, the Greeks waited for Artemis to intervene. The night after the Greeks appealed for her help, the Persians got lost in the woods and shot all their arrows in the dark, thinking they were killing their enemies, when they were just wasting their arrows on trees. Artemis is said to have misled them by putting them under the impression they could hear the cries of wounded soldiers falling on the ground. Left with no arrows or weapons to fight, the Greeks and their Goddess, Artemis, easily defeated them the next morning.