Etymology of "shiro"

I read a character called "the castle" in 訓 with "shiro" by the present, but there does not seem to have been the classical Japanese language "that I ever did" when I watched the history. I used the character called "the fence" other than "a castle" in an early medieval period from the ancient times and called it "ki" (barrier around a castle )(→ Castle (comes)). For example, I called a certain Oonojo "a shiver" near Dazaifu and seem to have called the Dewa fence of Yamagata "でわのき". As for each character, it will be “ じやう (= contemporary kana orthography later in a castle： I came to read じょう) "and a reading, a fence with "a fence".

The etymology of the reading called "shiro" seems to be such a thing. Because I proved right behind Mt. Nara seeing from the capital (Miyako) of Nara, it was named "Yamashiro" in a meaning called the back of the mountain and I was old and wrote the country (South Kyoto) of Yamashiro with "the cold dry wind blowing down from a mountain" in "Yamashiro", the seventh century. Because there was it with "this country natural stronghold, natural product Castle" when the Emperor Kanmu transferred the capital in Heiankyo, there was recognition that this country was a natural castle. You "should control 斯形勝 によりて, new" (794 years) on November 15 Enryaku era 13 years. You should do a cold dry wind blowing down from a mountain country some other time with a Yamashiro country. An Imperial mandate, edict or decree called "was given. I may have done the title with "unpleasant firewood" without remaining in 改字 because there was it when you "should have controlled new", but, actually, 訓(kun) of "shiro" still produced only a character only about "Yamashiro" and 訓(kun) じたので, character string called "Yamashiro" with "Yamashiro" some other time in "a castle". However, it was read because a reading of "Yamashiro" was equivalent to the land where a mountain made a castle, and the times I made a castle on the mountain, and to protect each fief visited it when "the castle" "did" it in the latter period in the Middle Ages. There is 訓(kun) of "shiro" in "the castle" to "a civilization book daily words dictionary" of the (1474) for civilization six years.