Ariel is a water spirit who was trapped in a pine tree by the witch Sycorax for twelve years before being discovered by Prospero, The Duke of Milan. Prospero sent Ariel to create a shipwreck upon The King of Maples ship with him and his crew aboard, though he asked that not one be harmed. So that's what she did, when she'd returned to give him the news she begged the magician to set her free in return for her services. Prospero denied but later recounted and set her free. Prospero then promises Ariel if she do as he wished, her set her free in two days time. For the rest of the show Ariel stays along side Prospero and follows the crew of sailors throughout their journey to Prospero. After all is said and done Prospero kept his promise and set Ariel free before returning home to his daughters wedding.
One thing Ariel is given which makes her so unique is her human edge and personality given by Shakespeare. Ariels is also commonly criticized for her gender. In textual version Ariel is always referred to as a boy, but in Restoration adaptation she's played by a woman. Ariel is a mulatto who, unlike the more rebellious Caliban, feels that negotiation and partnership is the way of freedom from the colonizers.
The Tempest had more stage directions then most of Shakespeare's plays, giving viewers the opportunity to see into the characters such as Ariel in his time. Example, when Ariel shows herself to Sebastian, Antonio and Alonso as a harpy, she’s directed to flap her wings on the table and make the food disappear by a device Shakespeare called “quainte device.” now nobody has been able to figure out what a “quainte device” is, but the actor would not be able to find the food themselves. Given her big wings she can't push the food off the table, and if she could where would she hide it? Later in Act 5 Arel says, “when I presented Ceres / I thought I had told thee of it / but I feared lest might I anger thee.” Viewers wonder if Shakespeare had intended on Ariel and Ceres being played by the same woman, and this line is Ariel admitting to it. The double role may have been caused by the lack of males capable of playing a female role. This was around the time that boys played all female roles.
It has not been determined where Shakespeare got the idea for Ariel. Spirits were viewed in either a religious or scientific standpoint. Religion sees them as either servants from god or servants of the devil. Science seeing them as neutral subjects which could be controlled by the wise.