A review article at Salon.com discusses this in terms of weddings, Scottish history, and even the origins of WWII:
July 9, 2009 | Let's start with something small. Many people believe that each of the tartan (plaid) patterns worn by Scottish Highlanders corresponds to a particular clan and that kilts made of this fabric have served as the uniforms and emblems of that clan since time immemorial. But, as the historian Hugh Trevor-Roper pointed out in a famous essay titled "The Invention of History: The Highland Tradition of Scotland," that simply isn't true. "Indeed," Trevor-Roper wrote, "the whole concept of a distinct Highland culture and tradition is a retrospective invention," cooked up in the 19th century. Much the same can be said of the customs of the "traditional" wedding (the elaborate church ceremony, the white dress, etc.), which were concocted a the same time. In fact, for most of the history of Christendom, a wedding was a low-key affair conducted at home without the benefit of clergy.
Yet kilts and bouquets have more common with simmering Weimar-era resentment than might initially seem. Even trivial "bad history," as MacMillan would call it, can be driven by profound desires. Trevor-Roper judged the "artificial creation of new Highland traditions, presented as ancient, original and distinctive," to be an attempt to assert a Scottish identity as a kind of protest against "Union with England." The idea of a gallant, free, Scottish tribal past appealed to the sensibility of the Victorian era as, too, did the notion of a very special white wedding dress; the first one was worn by Victoria herself when she married Prince Albert. Just as Scots thrilled to the idea of a rich native culture with deep roots, so we like to believe that the modern vision of wedlock as a union founded in true love is hallowed and eternal. Convincing ourselves that weddings have always been wrapped in sacred and sentimental rituals is like a charm against our suspicion that marriage may not be that romantic after all.
Being partly of Scottish descent, I had discovered that the tartans were of recent origin a long time ago, and I knew the whole thing about the white wedding dress and church weddings as well.
Like the tartans, much of the article speaks of retrospective creations that create ethnic and national groups:
Some people embrace "bad history" because it reinforces their national, regional or ethnic identity, as in the case of the Serbs or those Japanese conservatives who want archaeologists kept out of the ancient tombs of the royal family for fear that the remains found there will indicate that the emperors have non-Japanese ancestors. People seeking to keep the Irish divided once perpetrated the myth that only Protestants fought alongside the British in World War I, when in fact 210,000 Irish Catholics and nationalists volunteered. Others use the past to deflect attention from their own mischief, like the governing elites in China, who dwell on its history of colonialism, persecution and victimization at the hands of the West in order to invalidate any criticism from outsiders as more of the same.