Fall of Dol Guldur

The Fall of Dol Guldur was a retaliative attack from the Silvan of Mirkwood and Lothlorien. After Dol Guldur had assaulted the two elf kingdoms--and Dale/Erebor was busy being besieged, the elves of Lothlorien and Mirkwood struck out at Dol Gulder. Celeborn led the detachment from the south and Thranduil from the north. Nearing the end of the battle, Celeborn's wife, Galadriel laid bear the pits of Dol Gulder and fully purged the area of Sauron's taint.

After the battle, Celeborn and Thranduil met and divided Mirkwood up into northern and southern parts where each kingdom would rule.

Interpretations
Though the knowledge of this battle is limited, it has been suggested in games such as BFME2 and other games that what forces were left in Imladris and Lindon attacked Dol Gulder, the Woodsmen nearby may have participated, and Radagast himself probably participated in this battle as well.