The Woman Who Rides Like a Man - Tamora Pierce

Sir Alanna, the first female knight in living memory, cuts a unique figure - purple-eyed, lion rampant, a purple-eyed cat curled upon her saddle, she and her manservant Coram are captured by the Bloody Hawk tribe, a community of desert-dwellers. The Bazhir have strict rules and traditions that include the subjugation of women - Alanna's presence infuriates the tribe's shaman, who's convinced she spells doom, but the tribes' leader disagrees,a dn welcomes her into the tribe as a full member. She begins to teach three child outcasts her magic, as she sees the seeds of shamanism in them. When Ishak, the only boy, becomes arrogant about his abilities he retrieves a crystal sword brimming with malicious magic and, despite Alanna's efforts, he dies. Alanna decides that only she has the power to tame the sword, which will otherwise be a danger too anyone who finds it, and her will battles the power of the sword.
Jonathan is approached by the tribe to be the new Voice - a repository for the collective memories of the Bakhir and a unifying presence that will unite the city dwellers and the desert peoples. Jonathan wants to marry Alanna and, though she loves him, the idea of being tied down disquietens her. In the time they've been apart she thinks they've grown in different directions, and when Jon assumes that her hesitation is merely maidenly reticence she refuses his offer.
She falls into the arms of George, but he too wants her to change. When the Bloody Hawk chief asks her to check on his friend, a sorceress in another tribe, Alanna is pleased to investigate. Though she is ultimately unsuccessful, she learns of a stone, the Dominion Jewel, that can give great power to its possessor. Fearful that it will fall into unscruptulous hands, Alanna and Coram set out to find it.
An adventure story for young women, the Song of the Lioness series has a strong and principled female protagonist, a fact that augments rather than detracts from its enjoyment. Sometimes Alanna does come off a little too resolutely principled, and she is a little Mary Sue-esque in retrospect - without her everything would have come to an end not once but multiple times.
However, this is only in retrospect - as I was reading I was swept away by the pwer of the plot and the magnetism of the writing, and inspired by the strongly feminist ideals of the character. All of which makes the novel sound a lots less interesting than it is. - Alex