Complex sentence: Its one-character abbreviation is "辽" (pinyin: liáo), an ancient name for this region, which was adopted by the Liao Dynasty (Khitan Empire) which ruled this area between 907 and 1125.
Split into simpler sentences: Its one-character abbreviation is "Liao" (辽 pinyin: liáo). "Liáo" is an ancient name for this region, which was adopted by the Liao Dynasty (Khitan Empire) which ruled this area between 907 and 1125.