[Aangiras, p 276-277] says that there are 4 Manu - one is mythological and three are historical. All have been confused with each other.

(1) The mythological Manu is Manu Swaayambhuv, born from Swayambhoo (the Self-existent) He is consider the progenitor of the human race. The Sanskrit word "Manushya", the German word "Mannus" and the English word "Man" have their origin from the same Manu.

(2) The first historical Manu is Manu Vaivaswat, son of Vivaswat. Since Vivaswat means Sun, the Puraan called him the son of Sun, which is absurd. He is the first king mentioned in the Pauranik genealogies which start approximately from 3000 BC. It is stated in the Avestaa that the Aarya lived in Airyaanaa Vaejo (probably on the banks of rivers Ghorband and Panjshir to the south of Hindookush Parvat in Afagaanistaan), from where they migrated to Saptsindhu region in a boat because of the great floods which drowned a substantial part of the population. The Semitic people took this story from the Hindoo and changed Manu to Nooh which is the contracted and nominative form of the word of Manu. And from here it traveled to Old Testament where the word changed to Noah. The story of the flood in the Old Testament has the Hindoo origin. Manu Vaivaswat had 4 sons - Sudyumn, Ikshwaaku, Praanshu and Sharyaati; and not 10. They all founded their Dynasties.

(3) The second historical Manu was Manu Saavarni who lived approximately 120 years after Manu Vaivaswat. The two have clearly been distinguished in Rig Ved hymns 8-51 and 8-52, and yet later Pauraanik editors have confused Saavarni and Vaivaswat with the result that Naabhaanedishth, who was the son of Manu Saavarni, was foisted on Manu Vaivaswat as his son.

(4) The last so-called Manu was the author of Manu Smriti who did not give his own name to his book. Instead he he stated that the first man ever, means Many Swaayambhuv, was the author of Manu Smriti. One can only surmise that he did so in order to enhance the value of his work for the public, so that they can believe that it was written by the progenitor of the mankind. We would never the real name of this Manu and will always call the Manu who had written Manu Smriti.

Manu Smriti
Name of the Book of Law written in 2nd century BC. It contains 2,684 aphorisms dealing with civil law, criminal law and code of ethics and behavior, and lastly advice for worldly success and spiritual growth. Out of so many recommendations, only 126 are useful today. Yet 126 is a big number. Some of these 126 are remarkably brilliant and reflect the genius of the author and the saints preceding him. These 126 have been published under the editorship of Aangiras Muni in his book "Dharm Shaastra". Much of the contents of Manu Smriti is not only unacceptable today but will be found offensive in that it is full of caste and class bias.