Though known by many different names in many traditions,But there is only one God. Krishna is the original person. The word Krishna means the person who is attractive to everyone.
Sri krishna appeared over five thousand years ago in Mathura,dist of state UP (India) to Devaki and Vasudeva in the jail of Kansa. Kansa was the king og mathura and mama ofthe loard krishna .The place of His birth is known as Sri Krishna JanmBhumi.
The Supreme Lord descends from time to time in this material world to reestablish the teachings of the Vedas. In His Bhagavad-gita, Sri krishna promises: "Whenever and wherever there is a decline in religious practice, O descendant of Bharata, and a predominant rise of irreligion--at that time I descend Myself. To deliver the pious and to annihilate the miscreants, as well as to reestablish the principles of religion, I Myself appear milleniumm after millenium."
Although eternal the Lord appears in specific circumstances out of mercy for His devotees. In fact, His principal biography, the Srimad Bhagavatam states, "the learned men describe the births and activities of the Unborn and Inactive." Therefore, although He appears within the material dimensions of time and space, He is most definitely not of it.
Historically, Sri krishna appeared on the midnight of the 8th day of the dark half of the month of Sravana. This corresponds to July 19th 3228 BC. He exhibited His pastimes for a little over 125 years and dissappeared on February 18th 3102 BC on the new moon night of Phalguna. (His departure marks the beginning of the current age of corruption known as Kali.)
The great scholar Srila Vishvanatha Chakravarti neatly outlines Sri krishna's activities in this way: the first three years and four months were spent in Gokula, then equal lengths of time in Vmdavana and Nandagram, eighteen years and four months in Mathura, and finally ninety-six years and eight months in Dvaraka totalling 125 years of manifest pastimes. See the Krishna-lila chart.
In Mathura, both Krishna and Balarama were initiated by Gargamuni in the Gayatri mantra> Later They went to live under the care of Sandipani Muni who instructed Them in all the Vedic arts and sciences in sixty-four days and nights especially in military science, politics and spirituality. As an offering (guru-daksina) to Their teacher, They recovered his son from death. Although God does not need instruction from anyone else, Lord Krsna and His brother set the perfect example : one must accept instruction from and serve a bona-fide spiritual master to advance in spiritual life.
For the next eighteen years, They continued to live in Mathura halting the impending threat of many demonic kings. Later in Their pastimes Lord Balarama married a princess named Revati. Lord Krsna married many queens, the foremost among them being the extraordinarily beautiftil Queen Rukmini. Both Krishna and Balarama established Their palaces in Dwarka off the coast of western India.
Where They enjoyed married life for many years. Although They were married, Lord Krsna and Lord Balarama exhibited the quality of detachment from material life perfectly. When They were about ninety years old, the great world war of Kuruksetra took place. This climactic battle brought together all the major world leaders. Lord Krsna took the role of a charioteer on the side of the pious Pandavas, while Lord Balarama refusing to participate went on a pilgrimage tour thereby blessing the entire land of India.
At the start of the war, Lord Krishna displayed His stupendous Universal Form delivered His famous message known as the Bhagavad-gita, literally the Song of God. This Song contains the essence of all knowledge having been spoken by the Supreme Lord Sri Krishna Himself. This war concluded with the destruction of the demonic kings and the reinstatement of the righteous Pandava princes.
Having completed Their mission, Balarama and Krsna resumed Their life in Dvaraka where They spent some thirty-five more years before ending Their earthly manifest activities The foremost description of Lord Krishna's activities occurs in the Srimad Bhagavatam, literally "the Beautiful Book of God."