Bluestar

Bluestar-warrior-cats-of-pantherclan-28228378-1024-768.jpg'   Cats of the Clans
"Bluestar was a great leader, even if the price she paid for was higher then she ever dreamed. She gave Mosskit up on that snowbound night, Mosskit and her littermates, so that she could become Thunderclans deputy instead of Thistleclaw, who would have sliced through the forest until the paths ran red with blood. You should be proud of her for such loyalty to her Clan. Proud of Mosskit's father, Oakheart, too, for raising her brother and sister to be strong, respected Riverclan warriors.'

'''    Was Firestar a replacement for the kits Bluestar never saw grow up? An interesting question. She was an excellent mentor to the kittypet, and trained him to be a wise and confident warrior. She saw him as the Savior of her Clan from the moment the sun struck his flame-colored pelt. Spottedleaf had told her that only fire could save the Clan, so Rusty must have seemed like a gift from Starclan.'''

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It's to easy to say Bluestar went mad during the last moons of her life; You have only to think about what she gave up--including Mosskit-- to understand how far she thought she had failed. Don't forget that she gave up her ninth live to save her clan from the dogs, throwing herself into The Gorge to lead them to their deaths. Stonefur and Mistyfoot found her on Riverclans shore, so her final moment were spent making peace with her survivng children, before she came to join Starclan.​"=====

Warriors: The ultimate Guide
"Leader of Thunderclan before Firestar, Bluestar was a proud and deeply committed warrior. Once known as Bluefur, her early life was scarred by tragedy. Her mother was killed during a raid on Windclan and soon after, her sister, Snowfur, died on the Thunderpath. Isolated in her grief from her own clanmates, Bluefur fell in love with a Riverclan warrior named Oakheart, but their brief relationship ended when Bluefur realized she could not be loyal to Thunderclan while her heart lay elsewhere. Unbeknownst to Bluefur, she was already expecting Oakheart's kits.

Bluefur paid the highest possible price for her leadership, giving up her three kits in order to become deputy instead of Thistleclaw, whom she feared would destroy Thunderclan with his dark-hearted ambition. Oakheart raised Stonefur and Mistyfoot, the two kits who survived, in his own clan. Bluefur told her clanmates that her litter had been stolen by a starving badger, and then overcame her sadness to become deputy and leader as she had hoped.

When Bluestar was an apprentice, the Thunderclan medicine cat Goosefeather had delivered a prophecy to her: "You will blaze through the forest like fire; only water can destroy you." During her leadership, as Thunderclan struggled against its rivals, Bluestar looked to another source of fire--the red-pelted kittypet Rusty--to save her beloved clan. But Bluestar's murderous deputy Tigerclaw continued to rage against Thunderclan even after becoming leader of Shadowclan. He set a pack of ravenous dogs to raid the camp, and Bluestar gave up her ninth life to lead the dogs over the edge of the gorge, dying for the last time in water, just as Goosefeather had foretold. Starclan showed enough mercy that Stonefur and Mistyfoot found Bluestar on Riverclan's shore, and her final moments were spent making peace with her surviving children before she went to join her lost daughter, Mosskit, in Starclan."

Trivia

 * Bluestar had 4 deputies before death; Redtail, Lionheart, Tigerclaw, and Fireheart.
 * In an Erin Hunter Chat, it was revealed that Bluestar's name could have been Moonstar, but the Erins wanted to keep the prefix Moon- to the StarClan territories, the Moonstone and Moonpool. However, this is somewhat strange, because Bluestar's mother was named Moonflower.
 * In Bluestar's Prophecy, Bluestar told her Clanmates her kits had been stolen by a fox, but in The Ultimate Guide, it notes that she said a starving badger stole them.
 * Everybody thought that Redtail was the father of her kits. False; Everybody thought Thrushpelt was the father of her kits.
 * It is said that Bluestar didn't just like and trust Fireheart because of the prophecy, but because he reminded her of Oakheart. It is also said to be the reason why Bluestar gave him the suffix 'heart' for a warrior name.
 * It is said that everytime Bluestar crossed the Thunderpath she was reminded of Snowfur.

Taken from the book Warriors; Cats of the Clans by Erin HunterLink title    Taken from the book Warriors: The Ultimate Guide by Erin Hunter