slaves. However, the development of industry, trade and other branches of economy required skilled free workers that took interest in their jobs. A slave could get free by the act of manumission, by which a master would release him from his authority. Manumissions were different in different epochs. The old civil law (ius civile Quiritium) recognized three kinds of manumissions: Manumissio censu, was done by a master in the time of the Centuriate assembly. A master wishing to free his slave needed only to enter him in the censor's list as a citizen. Manumissio vindicta, was the liberation of a slave by a fictitious plea for freedom (vindicatio in libertatem). It was done before a magistrate when some citizen (adsertor libertatis) touched a slave by a stick (vindicta), and by right words said that the slave is a free man. If a master did not object to that claim (in iure cessio), a magistrate would validate the slave's freedom (addictio). This had been done under the old civil law (ius civile Quiricium)Manumissio testamento, was the liberation of a slave by a will. In a will master usually said "Stichus servus meus liber esto", and the slave would be free and without patron.Manumissio testamento fideicommissaria, was when a master asked his successor to release a slave. If that slave was made free, the man who released him became his patron.Manumissio inter amicos, was liberation of a slave by a statement in front of friends. Praetors protected these free slaves (by the Lex Junia Norbana, these people lived as free but died as slaves). This kind of manumission originated at the end of the republic.Manumissio per epistulam, same as above, just done by a statement in a letter.Manumissio per mensam was similar to the above manumissions. This one was not as formal as manumissions in time of old civil law, but had the same value as praetoric manumissions. Manumissions of this kind originated in the time of empire.Manumissio in ecclesia, were manumissions made in the time of Christian emperors in front of a priest. At the beginning of the empire, because of the number of manumissions, legal limitations of manumissions were made. These limitations were implemented by two laws: Lex Fufia Caninia and Lex Aelia Sentia. According to Roman law, slaves that were freed (libertinus, in regard to his master libertus) became Roman citizens, but they had many fewer rights than Roman