Britain's Prince Harry and his fiancee Meghan Markle. File picture: Darren Staples/Reuters

The marriage of a mixed-race US citizen into the British royal family would have been unthinkable a generation ago. Academic Chamion Caballero says that opposition to mixed-race relationships has fallen dramatically in Britain.

London - Meghan Markle describes herself as "half-black and half-white." She has written about the casual racism she experienced while growing up in Los Angeles and said she took "pride in being a strong, confident mixed-race woman." Now she is about to become the first member of Britain's royal family with African ancestry, at least in modern times.

Chamion Caballero, an academic and a director of the Mix-d Museum digital archive of racial mixing in Britain, believes the marriage reflects rising tolerance, but she has doubts about whether it will catalyse major changes in attitudes to race. The co-author of a new book, "Mixed-race Britain in the 20th century," discusses Meghan and the monarchy with dpa.

dpa: What does the marriage of Meghan Markle and Prince Harry mean for how the royal family is seen in Britain?

Caballero: I think that, as has long been the case with high profile interracial relationships, it will mean different things to different people as the wide range of views so far from the media, public figures and the public already indicates.

There are those who, like Jo Marney, the girlfriend of the former UK Independence Party leader Henry Bolton, are disgusted by the relationship, seeing it as tainting the lineage of the royal family. They view the royals' lack of opposition to the pair as symbolic of Britain's wider social capitulation to multiculturalism.

Meanwhile, there are others who have heralded the relationship as a cause for celebration for the very reasons it has upset people like Marney, such as the journalist and writer Afua Hirsch, who sees the monarchy's acceptance of the relationship as indicative of a growing recognition of diversity as an integral and ordinary part of British life.

And then there are some who, generally finding the whole concept of monarchy and celebrity irrelevant or tedious, simply do not care about the royal family and what Meghan's addition to it means.

dpa: And what could it mean for the status of African-Caribbean and mixed-race women, and men, in Britain?

Caballero: I think it is fair to say that, given the coverage so far, there is likely to be increased public discussion of the status of black and mixed-race women - and, relatedly at times, men - in Britain, along with their visibility. For example, in addition to Meghan herself, we've also seen her black American mother attract significant attention and commentary.

But as for making any link between the relationship and any actual, tangible change in the status of black/mixed-race women, I'm not convinced. I think [writer] Sathnam Sanghera's comment about being sure that "Meghan Markle will eradicate racism in Britain in the way a black president really solved all racism problems in the US" is probably on the money!

dpa: If Prince Charles had wanted to marry a divorced, mixed-race American 35-plus years ago, would it have been possible, socially and politically?

Caballero: As future head of the Church of England, it would have been impossible for Charles to marry a divorcee in the 1980s before the revision of the church's policy on divorce and remarriage, which only happened in 2002.

For the monarchy to approve of a non-white, non-aristocratic family to carry on the royal lineage would have been unthinkable, particularly in a social climate in which opposition to racial mixing was at times recorded as 50 per cent. Such attitudes, however, began to decline rapidly in the late 1980s.

dpa: Why is there so little opposition now?

Caballero: As we discuss in our book, large generational differences in levels of prejudice seem to be the driving force. This is not to suggest that there is a simple correlation to be made between a younger non-racist generation and an older racist generation - indeed, when we look at Twitter and other public forum comments, it is clear that racist attitudes towards interracial couples are not the preserve of older generations.

Rather, the general shift in attitudes by cohort goes some way to explaining why an impending interracial marriage at such a prominent level in the royal family hasn't attracted the open level of vitriol that it might have done several decades ago.

dpa: What do you think of US journalist Keli Goff's claim that Meghan would be less acceptable to the royal family if she had darker skin?

Caballero: I couldn't say whether she'd be less acceptable to the royal family, as I'd just be guessing their views.

But on a wider social level, I think it can be said with some confidence that it is likely that there would be even more prurience and racism visible in public discussions if Meghan had darker skin, as this certainly chimes with research findings on colourism and discrimination for darker-skinned women from black and Asian backgrounds.