Jewish Naming Practices & Confusion

Why the same Jewish person can have different names

AND

What Genealogists should look out for in Jewish Family Names

Many persons appear in genealogy charts and in historical different sources but they appear to be the same person  BUT where the spelling of their names is different or appears differently in differently in different places. OR they may at first glance appear as different persons when they are the same.
Their Matzevah (Tomb Stone may say something completely different than their civil marriage records which is different than their civil records which is different than what your Zaida (grandfather) called him/ her.

Jewish Family Names
Its should be noted that  Family names only became a universal practice during the 19th century when many states forced Jews to take on family names. How ever there were many Jewish families who had maintained a family name in some form or another for centuries until that point (eg Rothenberg Family, Katzenellbogen, Goldschmidt, Wertheim(er), Oppenheim(er) etc.).Family names were well established in Spain Portugal and the Iberian Peninsula from the 12th /13th Centuries (eg Henriques Family, Yachia/Jachia, Abrabanel,  etc.)

Different Customs
Ashkenazic Jews frequently name newborn children after deceased family members, but not after living relatives. 
Sephardic Jews, on the other hand, often name their children after living relatives

Jews with Different Names BUT the Same Person:
The same Jewish person may be recognized by several names such as::
    *     Civil Name - used in civil or state proceedings
    *     a kinnui or “popular” name “popular” name, by which Jews were known to their coreligionists and which appears in the Jewish records, this was often the patronymic name; 
    *     a Yiddish name (which may be the same as the kinnui or “popular” name
    *    a Title or honorific name - refer to such famous rabbis and scholars as  ReMa or Chiddushi HaRim or Sfas Emes
    *    a religious name - eg Schmuel ben Ya'acov Ha Levi (ie Schmuel son of Ya'acov a Levi - member of the tribe of Levi who had a specific role in a synagogue and who passed that status as a 
             Levi down to his son)
and
    *    a Patronymic name

Now, many times these names are mixed up or added together. Even more common they were written / spelt differently, this especially applied to names which were translated from Hebrew  to the Romanized or local script. So Ruben, Rueben, Ruebin, etc are the same name trnsliterated differently.

So some times our Schmuel ben Ya'acov Ha Levi may be recorded as Schmuel Ya'acov HaLevi, even his sister may be called Sarah Ya'acov Ha Levi - which is patently WRONG.as the family name may not be HaLevi. The name Schmuel Ya'acov is his Patronymic name.   that is his hebrew name plus his fathers hebrew name minus the "ben" or "ber" (son of).

In the civil records he may be known as Samuel Goldschmidt, but when he moved to Cassel and started a family his name may appear to be  Samuel Goldschmidt-Cassel or just Samuel Cassel.

Now when his son Moses moved to Oldenberg he could be called Moses Goldschmidt-Oldenberg or Moses Oldenberg-Goldschmidt or just Moses Oldenberg his first name may even be (and often is recorded as ) Moses Samuel.
If the family moved to Holland the name may become Goldsmid, and if they moved to England it may become Goldsmith, and if they married a famous (eg the Rothschilds) Family it could become Goldschmidt-Rothschild.

It is also NOT uncommon for families to take on the family name of the wifes / mothers family.

Place names and Jewish family names:
It was not uncommon for Jews when forced to take on family names to take on the name of the city in which they lived (so not all Bacharach's are related although their ancestors at one time may have lived in Bacharach)
Jews may just have taken on that place name for some convenience or to identify them selves to the civil authorities, so in the Goldschmidt family there are Kassel, Cassel, Oldenberg, Hameln, Stuckert, Stadthagen, Emden and they are offen written as Stadthagen-Goldschmidt or Cassel-Goldschmidt (all these places are towns around Hessen Germany where they lived or moved to). An example of this is Wolf Goldsmid who occurs in Jewish sources as Wolf Kassel (the town in which he was born), 

Jewish Names from professions:
Similar to place names, when forced to take Family names some families took that of their trade or profession (eg Schnider Tailor, Schumaker = Shoe maker, Goldschmidt = Goldsmith, etc)

Jewish Family Names Morphing names through ages and residences:
Just as these civil names morphed depending upon where they lived, so did they change in spelling
Goldschmidt in Germany, Goldsmid in Holland, and Goldsmith in England.
or Rothenberg in Germany, Rottenberg in Poland, Rottenborg in Denmark and Holland, and even Rotenberg at other times in other places. Where as the Chiddushei HaRim Rabbi Yitzchak Meir Rothenberg became Rabbi Yitzhak Meir Alter (they say when he was hidding from civil authorities). From him came the whole Alter  family that is the dynasty of  Gerrer Hassidim.

What about Schmoll, Schmuel, Shmoul, Samuel, & Sam ?
How more confusing can you get when the same person has a Yiddish name, a Polish name, an English name, and a popular name when they immigrated to the USA ?

It is even more confusing and difficult to track through the records when an individual was known as Paulo De Millao, also called himself Paul Dirchsen and Paul Abensur and his son was known as Josa Henriques and Josa Abensur.
This practice became even more common when Jews migrated to countries like the USA and changed their names in order to assimilate. 
OR
In Israel today where many new immigrants change their "non Jewish" names to Hebrew names.

Jewish Names Conclusion:
Be wary of names when you write up your family tree
Be careful to check that the person you are investigating is really the person you are related to or that your ancestor is related to.
Do NOT put your own *(mis) interpretation on names - my name is Mordechai - one correspondent insists on calling me Mordechay (for ideological reasons "a "yud" in hebrew is a "y" in English)
another Hossid friend writes in his "yiddish" vernacular Soro rather for some one every one else calls Sara  onm the basis that "yiddish" is authentic Jewish language. !
Don't make up names from hebrew names as Schmuel Ya'acov from Schmuel ben Ya'acov
Don't be put off by different family names between parents and children.

Please find below outlines of some other naming issues:

Sephardic Naming Practices (<- Click Here)

Naming practices among Ashkenazi Jews (<- Click Here) by Dr. Jona Schellekens, Department of Population Studies, Hebrew University of Jerusalem  

Patronymic Names what are they ?(<- Click Here)