LONDON — For many in the British news media, the engagement of Prince Harry to Meghan Markle, a divorced biracial American, reflected how egalitarian Britain had become.

“A divorced, mixed-race, Hollywood actress who attended a Roman Catholic school is to marry the son of the next king,” began the lead editorial on Tuesday in The Daily Telegraph, a conservative newspaper. “Such a sentence could simply not have been written a generation ago.”

It was a sentiment — with some notable cautions — that echoed across political and ethnic boundaries.

Afua Hirsch, the author of “Brit(ish),” a coming book about racial identity in Britain, said that as a mixed-race child she had found it hard to reconcile her British-ness with “the family at the apex of society,” the racially homogeneous relatives of Prince Harry.