How would one trace royal families?

Question

Specifically, how would one deal with minor royalty in Spain before the Reconquista?

Preferabely free methods, if possible.

Answer 1

Some libraries carry genealogy records.  But in this case you might want to start with what you know and see if you can find a possible link.  It might get hard when you get to current times,  Genealogist have age cut offs on what they can acceptably publish on living people.  What I would do is go get a book on the subject and use the sources that the person listed as a start.

Answer 2

The royal house to which the monarchs of Spain belong to is the Bourbons,they are quite known,Wikipedia must have a family tree

Answer 3

Try searching Spanish Peerage on the internet.  You can find all kinds of interesting stuff, but most of the interesting stuff I've found asks for money to delve more deeply.  Sorry.  That may just be all there is.  What, specifically, are you looking for?  I might just have already found it.