Hi,

I enclose the same reply as I have just given someone else in another post:

First of all you need to find out in which year your grandfather left Spain and which were the reasons. This is important in order to determine whether you can opt for citizenship via' La Ley de Memoria Histórica' ( which will enable you to obtain Spanish citizenship without having to reside in Spain previously) or if you will need to reside in Spain for one year before you can claim it.