<P> The series was officially picked up on May 6, 2015, after receiving a series commitment in September 2014, and received a full season order on November 30, 2015 . Since the second season, which was ordered in May 2016, the series has aired on The CW . On April 2, 2018, The CW renewed the series for a fourth season, which premiered on October 14, 2018 . </P> <P> Kara Zor - El was sent to Earth from Krypton as a 13 - year - old by her parents Zor - El and Alura . Krypton was exploding, and Kara's parents sent Kara in a spacecraft to Earth after her cousin . Kara was meant to protect her infant cousin Kal - El, but her spacecraft was knocked off course and forced into the Phantom Zone, where it stayed for 24 years . By the time the spacecraft crash landed on Earth, Kal - El had grown up and become Superman . The series begins eleven years later when the now 24 - year - old Kara is learning to embrace her powers and has adopted the superheroic alias "Supergirl". </P> <P> In the first season, Kara is forced to reveal her powers, and becomes National City's protector . Kara discovers that hundreds of the criminals her mother imprisoned are hiding on Earth, including her aunt Astra and Astra's husband Non . Kara works with her adoptive sister Alex Danvers to fight these criminals, alongside the Green Martian J'onn J'onzz, her cousin's friend James Olsen, and tech genius Winn Schott, Jr . </P> <P> In the second season, Kara and her allies deal with feuds between Earth's native populace and extraterrestrial community, and investigate the shadowy organization Project Cadmus, masterminded by Lillian Luthor, mother of Lex Luthor . At the same time, Kara befriends Lillian's stepdaughter Lena Luthor, the new CEO of LuthorCorp, and struggles with romantic feelings for recent Earth arrival Mon - El, a princely survivor from Krypton's neighboring planet Daxam whose parents wish to reclaim him . James becomes the masked streetfighting vigilante Guardian; Alex begins dating Maggie Sawyer; and J'onn befriends a younger Martian, M'gann, from the White Martian race that killed his people . </P>

What city does supergirl protect in the show