289 From a letter to Michael George Tolkien 

29 July 1966

Mirkwood is not an invention of mine, but a very ancient name, weighted with legendary associations. It was probably the Primitive Germanic name for the great mountainous forest regions that anciently formed a barrier to the south of the lands of Germanic expansion. In some traditions it became used especially of the boundary between Goths and Huns. I speak now from memory: its ancientness seems indicated by its appearance in very early German (11th c. ?) as mirkiwidu although the *merkw- stem 'dark' is not otherwise found in German at all (only in O.E., O.S., and O.N.), and the stem *widu- > witu was in German (I think) limited to the sense 'timber', not very common, and did not survive into mod. G. In O.E. mirce only survives in poetry, and in the sense 'dark', or rather 'gloomy', only in Beowulf 1405 ofer myrcan mor: elsewhere only with the sense 'murky' > wicked, hellish. It was never, I think, a mere 'colour' word: 'black', and was from the beginning weighted with the sense of 'gloom'. ....

It seemed to me too good a fortune that Mirkwood remained intelligible (with exactly the right tone) in modern English to pass over: whether mirk is a Norse loan or a freshment of the obsolescent O.E. word.