where someone ordains and they give them a new name. did this start in the time of the buddha? as far as i can tell ananda was still ananda after ordination and many others retained their names.
when and why did they start giving everyone new names?
Actually not every bhikkhu is given a new name. In Thailand, for example, many common male names are from Sanskrit and it’s quite common for the original name to be simply changed to its Pali form when the man ordains. For example, if a Thai is called Kasem (from the Sanskrit ‘kṣema’) there is a good chance that he’ll be given the name Khema or else a compound name that starts with Khema-.
However, it is true that most men are given a new name, but I don’t think it’s known when this practice began. Certainly there’s no evidence for it in the Canon and as far as I recall the practice isn’t described even in the commentaries.
My own guess is that it probably began when the sangha migrated to regions where people had names that ended in consonants or in unsuitable vowels. The Vinaya requires that the Pali formulas recited in the course of an ordination ceremony be correct in pronunciation, grammatical form, etc. and certain departures from the rules would render an ordination defective. In Pali every name ends in a, ā, i, ī, u or ū. If you have a name that ends in some other letter then there would be no established way of inflecting it according to the principles of Pali accidence and so it would need to be modified to a phonetically more suitable form. For example, you’d have to change Bruce to Brūsa and Fredrick to Vedrika. But then since such modifications would generate names that are meaningless in Pali, you might as well just give the man a completely new name.
David: Upatissa and Kolita became Sariputta and Moggallana.
But these weren’t new names. Moggallāna was Kolita’s brahminical gotra name (he was from the Maudgala gotra) and Sāriputta was Upatissa’s matronym (his mum was called Sārī). Most of the Buddha’s disciples of brahminical birth are called in the Suttas by their gotra names, for example all the various Kassapas, Kaccāyanas, Koṇḍaññas, Vacchas, Bharadvajas, Piṅgalas, etc.http://en.wikipedia.org/wiki/Brahmin_gotra_system
The Vinaya has a story which offers a clue as to why this is so. It tells of how Mahākassapa wished to ordain a man and summoned Ānanda to act as the announcing ācariya. Ānanda repeatedly tried to dodge taking part in the ceremony. Eventually he was summoned by the Buddha and asked to justify his conduct. Ānanda explained that if he were to take part the Vinaya would require him to announce Mahākassapa as the preceptor using the man’s personal name, Pipphali. But he held Kassapa in such high esteem that he had never called him Pipphali even when speaking about him in the third person. The Buddha then amended the rule, permitting gotra names to be used when making this announcement. And so from this it would appear to be a matter of courtesy that gotra names predominate over personal names in the Suttas. Perhaps this also accounts for why the Buddha’s personal name (given in the commentaries as Siddhattha) isn’t mentioned at all in the Suttas.