Nanluogu Xiang is a neighborhood which has traditionally housed merchants, the wealthy and the powerful, and it's well on its way to reclaiming that heritage today. It existed in the Yuan dynasty and it wasn't until the Ming that it began to assume its current form. Before 1750 its official name was Luoguo Xiang (罗锅巷, Arched or Humped Street), but following a city-wide mapping project in that year, it's present name was adopted.
Nanluogu Xiang has always been home to great personages – Chiang Kai-shek, Mao Dun, various princes, Pu Yi's concubine Wan Rong, the present remnants of Pu Yi's family, and so on.
Since the turn of the century Nanluogu Xiang has become out-and-out trendy, hosting bars and cafes and backpacker hostels. It got a makeover in 2006, with new paving stones, and they're calling it a 'quiet bar street' (静吧街), presumably to differentiate it from the discordia of Sanlitun.