Follow along as Rolls-Royce puts the final touches on its stately Cullinan SUV

Rolls-Royce Cullinan test mule

Bentley raised eyebrows at the 2015 Frankfurt Auto Show when it introduced the all-new Bentayga, its first-ever off-roader. It was a controversial model. Purists accepted it, haters stopped howling, and the Bentayga now stands out as Bentley’s most popular model in key markets like the United States and China. Former sister company and current arch-enemy Rolls-Royce has entered the final stage of developing its own SUV to compete in the same ring with the Bentayga.

Named Cullinan, the high-riding model will ride on a platform designed in-house. This ends the rumors claiming it would share its architecture with the upcoming BMW X7. Lightweight materials like aluminum and, possibly, carbon fiber will keep weight in check. Still, this is a Rolls we’re talking about; it won’t exactly be a lightweight. To add context, the newest Phantom weighs over 5,600 pounds.

Bentley designed the Bentayga to go off the beaten path, a claim Digital Trends has verified on several occasions. Rolls-Royce predicts the Cullinan will simply be an all-terrain vehicle, not a full-on off-roader capable of following a Jeep Wrangler on the grueling Rubicon Trail. In spite of that, the BMW-owned carmaker boldly claims the soft-roader will be better than its Bentley-badged competitor in every way.

“The Bentley SUV is clearly the No. 2; Rolls-Royce is the best in the world and will be when our model arrives. We will bring a great new car, and an authentic Rolls Royce into the market,” promised company CEO Torsten Müller-Ötvös shortly after the Bentayga made its official debut. That’s fighting talk, and we can’t wait to see the two ultra-posh off-roaders duke it out.

The Cullinan’s development process continues. Rolls-Royce teamed up with National Geographic to film and photograph the SUV on a daily basis as it conquers the harshest terrain on the planet as part of its shakedown testing. It will tackle sand dunes in the Middle East, fry-an-egg-on-the-hood hot temperatures in the American desert, and the frozen, snow-covered parts of Europe that lie above the Arctic Circle.

The Rolls-Royce Cullinan will make its public debut before the end of the year. We don’t know yet if it will break cover at an auto show, like this year’s Los Angeles Auto Show, or if the brand will choose to hold an Apple-style stand-alone event. Regardless, it will arrive in showrooms next year with a price tag well in the six digits. When it lands, it will compete in the same segment as the Bentley Bentayga and the recently introduced Lamborghini Urus.