My objective was to research how the cult was recieved by the local populace, the Iberians who lived there before the Romans settled in the region.
I also wanted to figure out how long it took before it was properly integrated with the local populace.
Like pointed out, this doesn't mean that you have to have a completely unique subject, but rather a subject that you can properly explore and do something with.
Just because the Holocaust has been studied before doesn't mean that it has been fully explored, or that what's been concluded is now absolute truth.
Or just because it is generally accepted that the Roman empire didn't fall because of lead in the pipes, it doesn't mean that you can't do a study on that subject.
However, if you choose a subject like that, a subject that's been well studied in the past, it is important that it is your data that is presented in the study, not another author's.
There is of course a big difference between the time a ruling power - in any kind of state - decides upon something, and the time when it is commonly accepted by the people living there.
To add on to /u/k1990's point here: there is a rather clear difference in the finished studies between the students who've made an effort before starting the study and those who just picked someone and went with it (or worse, those who change subject midway).
Tell me your experiences in writing your dissertation at undergraduate level so that i may gain a wide scope of ideas! EDIT: Thank you all so much for finding the time to post such detailed advice.
All your topics sound so interesting, and it's great to see so many obscure topics being discussed and not your average unoriginal subjects that there's already so much on.