The Arya Samaj was founded by Maharishi Swami Dayananda Saraswati, a sanyasin (renouncer) who believed in the infallible authority of the Vedas.
Arya Samaj is not a religion but is seen as a society which culminates all like minded noble people (Aryas) believing in Vaidik Satya Sanatana Dharma (commonly called "Hinduism").
Established on April 10th, 1875, formally in Bombay, the main motto behind Arya Samaj is "Krinvanto Vishwam Aaryam" (Rig Veda 9.63.5) - Make all men Aarya (noble and cultured).
The ten basic principles of Arya Samaj are:
God is the primary cause of all spiritual and physical sciences and of everything known through their means.
God is Existent, Intelligent and Blissful. He is Formless, Beginning less, Incomparable, the Support and Lord of all, Omniscient, Imperishable, Immortal, Fearless, Eternal, Holy, and the Creator of the Universe. To Him alone worship is due.
The Vedas are the scriptures of all true knowledge. It is the duty of all Aryas to read them, hear them being read and recite them to others.
One should always be prepared to accept truth and reject untruth.
All action should be performed in conformity with Dharma (righteousness), that is, after due consideration of the right and wrong.
To do good to the whole world is the main objective of the Arya Samaj, that is, to improve the physical, spiritual and social well-being of all mankind.
All people should be treated with love, fairness and due regard for their merit.
One should always promote knowledge and dispel ignorance.
One should not only be content with one's own welfare, but should look for it in the welfare of others also.
One should be bound in following altruistic, social rules, while all should be free in following the rules of individual welfare.