After the coming of Sauron to the southern reaches of Greenwood the Great, and the spread of the Shadow from his fortress of Dol Guldur, the once-bright greenwood became a dark and dangerous place. To reflect this change, the Elves gave it a new name: some sources suggest they chose to call it Taur-nu-Fuin, the 'Forest under Nightshade', doubtless in memory of a similar dark forest of the First Age. Other sources give an alternative Elvish name, Taur e-Ndaedelos, meaning 'Forest of the Great Fear'. These Elvish names are generally translated using probably the best known form of the forest's name: 'Mirkwood'.