Satoshi* Nakamoto is the pseudonym of the person or group of people behind the inception of bitcoin. Its identity remains unknown.
* 1 bitcoin can be divided in 100 million parts, being 0.00000001 BTC the minimal, undivisible unit one can conceive in bitcoin. This minimal unit is also called "satoshi" in honor of the creator.
Some say that a real artist doesn't need to sign its works, which is other way of saying that a true artist doesn't seek the praise of others. The real reward comes in other two different ways: the process of creating the work and to see how that work impacts in others. If we adhere to this definition, we can say that Satoshi Nakamoto is a true artist.
We can be pretty sure that Nakamoto is proud of how bitcoin is changing the world and doesn't need any recognition for its contribution, there are far more serious reasons to stay behind a mask. Bitcoin is threatening the way our financial system works and has already triggered some important changes on it; it's better if such powerful people has no one to blame to (and search for).
As you may imagine, the history behind the creator of bitcoin commenced before the bitcoin itself. Although the bitcoin was published in January 2009, the first appearance of Nakamoto on the internet goes back to 31st October 2008, when a post with the subject "Bitcoin P2P e-cash paper" was published in a cryptography mailing list by the user "satoshi at vistomail.com" and signed by Satoshi Nakamoto. You can see an archived version of the post.
By that moment, the domain name "bitcoin.org" was already registered and active, containing the paper* with all the technical specifications. The document is still published today.
Our current finacial institutions work under a fractional reserve system which has proven to bring us more economic imbalance decade after decade, but we have had no alternative to preserve and use our funds. As you can read from the paper:
A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution.
At the moment of starting the bitcoin network, Nakamoto would be even more clear about the motivations behind bitcoin, just like we're going to see now.
The 3rd January 2009 Nakamoto implemented the bitcoin software thus starting the bitcoin network. At the same time, the bitcoin software was published as open source code. The first created block, also called genesis block, included the following message on its metadata, clearly refering to the instability produced by the banking system:
The Times 03/Jan/2009 Chancellor on brink of second bailout for banks
From the moment the bitcoin was published and implemented, the role of Nakamoto consisted in collaborating with the community formed by the first bitcoin enthusiasts and helping them understand the concept of bitcoin itself. All because he wouldn't stay there forever; in fact, he would stay there just briefly.
In December 2010 Nakamoto announced his departure and gave the control of the code repository to Gavin Andresen, which later put this control in decentraliced hands.
If we have to tell the history of Nakamoto in a few words, we would say that he published the bitcoin, helped the community to understand it enough to be able to take the control of its development and then gave this control to a trustworthy person.