1 is correct.
Things 'date back' for a length of time.
It dates back 500 years.
It dates back millennia.
Things 'date back TO' a specific period or point in time.
It dates back to the 15th century.
It dates back to the 1940s.
'Dates from' is like 'dates back to' - it uses a point or specific period rather than a length.
It dates from the 15th century.
It dates from the 1940s.
(Though I think dates back to sounds better.)
To correct 2, you could say:
It dates from several centuries AGO.