The term bloody is often used in phrases such as "the bloody car won't start!" or "why won't this bloody thing open up?". I'm interesting in knowing not only how this phrase originated, but how it developed over time. Did it start out with the same purpose it serves today, or did it have an entirely different meaning in the past?
According to the Oxford English Dictionary, the origins of bloody as a negative intensifier are unclear. Bloody, as an adjective, pre-dates the early modern period, but it seems to emerge as a negative in the early modern period (c. 1600).
The association with the blasphemous Shakespearean oath "'sblood" (Christ's blood) - appears often, though the OED editors discredit the association as "unlikely" due to other developments.
Despite the hesitance of the connection to Christ's blood, the etymology cites occurrences of the phrase "bloody whore" (potentially related to the Whore of Babylon") and "bloody drunk" which could have Reformation era connotations of priestly abuse (Stefania Biscetti disagrees with this on grammatical grounds). The appeal to this potential folk-etymology is that late-medieval Christianity certainly elevated Christ's blood -- as an object for meditation, the rise of "bleeding host" shrines, and the importance of the Eucharist. Caroline Walker Bynum's Wonderful Blood is a great source for this. Thus, bloody works on a blasphemous level (profaning the sacrament of Christ's blood), and/or it works as a Protestant slight against perceived Catholic idolatry.
edit: I can't really speak to the evolution of the term beyond it's apparent origin in the 16th and 17th centuries. The OED refers to George Bernard Shaw's Pygmalion that still had public outcry in 1914. It suggests the "normalization" began in Australia.
Can anybody comment on 'vachement' in French, which is apparently somewhat of an equivalent? It seems even more bizarre than 'bloody'.