With sumptuous costumes and a cast including a couple of familiar and beloved costume-drama players, Starz’s “The Spanish Princess,” about the travails of Catherine of Aragon, seems designed to appeal to lovers of broadly drawn historical romance. (It hits the air May 5 with a built-in fandom: Like past Starz miniseries including “The White Queen,” it is based on the writing of novelist Philippa Gregory.) And yet it’s hard to imagine anyone outside the core constituency for royals and the games they play finding much of interest in “The Spanish Princess”: Baroque in its attention to detail, but telling its version of history strictly for the fandom.

Part of the problem — one that grows increasingly difficult to look past, even despite all the finery on display — is the character at the show’s center. Catherine, who arrives in England as a teenager in order to cement an alliance between the besieged kingdom and her native Spain, is a cipher throughout. Charlotte Hope, the English actress playing Catherine, is saddled both with an unwieldy accent and a character biography that encompasses little more than the will to power. The mere fact of Catherine’s getting agency in a story that tends to focus on her husband and her misfortune is certainly notable, but one searches for the second beat, the thing this show has to say. And her integration into the royal court is attended, primarily, by either culture-clash comedy that’s a bit unworthy (“Siesta? Is this a food?” asks Dame Harriet Walter as Margaret Beaufort, the grandmother of the prince who will become Henry VIII) or by florid chaos. Her courtiers pay her obsequiously devoted attention, calling her “the light” and “infanta”; we never meet the saintly figure they love, really, nor the figure who draws such ire from the Brits. Catherine, here, is motivated by becoming queen, but there’s got to be more to the story than that. Moments where it feels as though there might be are those involving Walter and “Downton Abbey’s” Laura Carmichael, who in their respective manners (Walter imperiously, Carmichael through pained, heightened suffering) help elevate their scenes towards a fun dynamism that’s absent elsewhere.

But the character deficit, here, runs into the fact that a more richly written Catherine might be more compelling to follow through a real-life political drama. She had been promised from childhood as the bride to regal heir apparent Arthur (Angus Imrie); it spoils only history to note that the path, once she arrives on England’s shores, does not run so smooth. The inability to crack her character — and the show’s insistence on larding on complications including subplots among her courtiers and dream sequences, as if to redress its inability to connect the dots on its title character. Late in the limited series’s run, Catherine asks the future king she knows as Harry (Ruairi O’Connor) what the drama at court is about. “You, of course!” he shouts back. “It’s always you!” That’s true enough: Catherine is certainly at the center of the show’s maelstrom of action. But the woman worth getting angry over is nowhere to be found, here, in a show that earned my polite admiration but not my fealty.

“The Spanish Princess.” Starz. May 5. Eight episodes (all screened for review). 

CAST: Charlotte Hope, Stephanie Levi-John, Nadia Parkes, Aaron Cobham, Dame Harriet Walter, Laura Carmichael, Ruairi O’Connor, Elliot Cowan, Alan McKenna, Angus Imrie, Alexandra Moen, and Georgie Henley.

EXECUTIVE PRODUCERS: Emma Frost, Matthew Graham, Colin Callender, Scott Huff, Charlie Pattinson, and Charlie Hampton.