What do you mean came first?
If the sharingans origins lie in the byakugan, logically, the byakugan came first.
The one which was sensitive to light came first lol, but the manga did say that the first Dojutsu was the rinniegan .....
They say. And Rumors say....its not really a factual statement.
urg should've stated it more clearly... of course the rinnegan came first, but the examples show the sharingan before the Leaf was formed and kakashi who stated that the leaf's oldest eye technique is the byakugan
of course this could be me functioning on loss of sleep while studying
Well I believe the Rinnegan came first, but I don't believe it spawned the Sharingan and Byakugan though. Im not completely sold on the assumption that Sharingan descended from the Byakugan. I believe they existed as separate eye techniques (as in one didn't spawn the other).
I don't thing the Sharingan and Byakugan have any relation, maybe Kakshi was just telling them stories so t hat they think he knows everything lol........But my guess is that the Byakugan came from the Senjutsu clan and it is quite and the Sharingan from the Uchiha clan...