From Liu Yuxi's 《
乌衣巷》 (Tang dynasty):
朱雀桥边野草花,
乌衣巷口夕阳斜。
旧时王谢堂前燕,
飞入寻常百姓家。 'Wang' and 'Xie' are the Wang Dao and Xie An clans, the dominant aristocratic families of the Eastern Jin dynasty, whose mansions stood on Wuyi Lane in Jiankang (modern Nanjing). By Liu Yuxi's day, their glory was long gone; only the swallows remained, now nesting among commoners.