During the White Council, there is mention of a hard-fought battle against Sauron and a 400-year peace.
The "hard-fought battle" was presumably the War of the Last Alliance at the end of the second age, but the "400-year peace" can only refer to the time 2063-2463 where Sauron left Dol Guldur temporarily.
Of course, this was almost 500 years prior to The Hobbit, so the timeline is really messed up :-)