Civis Romanus sum
In Italy there is the ius sanguinis, or the right to obtain Italian citizenship if an Italian is present among your direct ancestors. There is no limit to the number of generations (the ancestor could also be lived in the Eighteenth century or earlier), but there are several conditions to be respected (for example, women transfer their citizenship to their children only if they were born after 1948, otherwise a process must be instructed).
Given the high rate of emigration recorded in Italy at the beginning of the twentieth century, mainly directed towards the United States and South America, many people aspire to obtain Italian citizenship.
HOW DOES IT WORK
To be able to apply for Italian citizenship it is necessary to demonstrate with no doubts that you are descended from an Italian ancestor, and to do this you need to compose your own direct family tree first with the local documents and, finally, with the Italian ones: extracts of birth, marriage or, when not available (because they are too remote) with certificates of baptism or marriage issued by the Dioceses.
The documents must be stamped and signed by the competent officer or by the reference Diocese; once obtained they must be presented in original (hard copy) to the Italian Consulate of your country.
The cost of this service varies greatly, as it depends on “how much information” you know about your Italian ancestor: if you know year and city of birth for sure, the cost is only 50 € (adding the original home shipping).