The problem of alienation and loneliness has preoccupied sociologists for over a century. As European cities grew in the late 19th and early 20th century, a new tranche of urban office jobs drew thousands of lower-middle-class workers who were seen as concerningly untethered from the bonds of community and family. After glossing the 20th-century history of romantic loneliness, this chapter focuses on the implications of changes in sexual and romantic custom on single selfhood, focusing on the period after 1970. After a peak in 1972, marriage rates plunged, and singles, including divorcees, were recognised as both a newly significant demographic (a cause for concern) and a spur to the rapid expansion of a cottage-style dating industry. Here, I set the gender-political changes of the 1970s and their consequences for the romantically questing into a longer historical context of romantic loneliness in 20th-century Britain.