After debuting at Venice and Toronto in September, Stephen Frears’ playful period drama Victoria & Abdul surprised absolutely no one by immediately becoming one of the awards-buzz titles of the season, scoring a cool $9.4m on release in its native UK. With Oscar-nominated Mrs. Brown star Dame Judi Dench reprising that critically acclaimed film’s role as Queen Victoria, Frears’ latest tells the little-known story of how the long-reigning monarch – and then-empress of India – became good friends with Abdul Karim, a low-ranking servant who attended to the queen in the last 15 years of her life and became her “munshi” (an Urdu word for “teacher”).

Though it begins with a tongue-in-cheek disclaimer saying that the film is “based on true events … mostly”, Victoria & Abdul is, according to author Shrabani Basu at Friday’s The Contenders London panel, really quite faithful, staying something like “80 percent” true to the facts. So true, in fact, that DP Danny Cohen described the shoot as “a nightmare” since it was shot at some of the original English Heritage sites where the events took place. “They wouldn’t let us put up any lights, and to move anything needed the permission of three people,” he recalled. But when speaking to Deadline’s Nancy Tartaglione, Basu surprised the audience at BAFTA’s 195 Piccadilly HQ by revealing that she had only come across this fascinating slice of history by accident.

“It all actually started with curries,” she laughed. “For an earlier book I was researching the history of curries, and I knew that Queen Victoria liked her curries, and she had some Indian servants.” But it was only on a trip to the Isle of Wight, to Queen Victoria’s holiday home there, that Basu realized there was more to the story. At Osborne House, she noted, “there is an Indian corridor there, and there was a portrait of Abdul Karim, in red and gold and cream, and he’s holding a book. It struck me that he hadn’t been painted like a servant. He looked more like a nobleman, and that aroused my curiosity.”

From there, Basu went to another royal residence – Windsor Castle. She recalled, “I asked to see the archives – her journals, Queen Victoria’s Hindustani journals, which are the journals she kept in Urdu. And I was expecting a small exercise book with a few phrases [in it] because I knew she’d learned a bit of Urdu. But the archivist wheeled in a trolley with 13 volumes there, and then I said, ‘Well, I’m going to be here a long time!'” She laughed. “But I went through all the 13 volumes, and nobody had opened these. You know, the blotting paper fell out in my hands! It was amazing! There were just little entries there that were so personal.”

After four years of research, Basu finally came across Karim’s diaries, and the full story started falling into place. “It was a long journey,” she laughed. “Three countries and three palaces. But it worked.”