At Telouet, in the High Atlas, the guardian came from his prayers with a key the size of a small shotgun. For a moment, he struggled with the antique lock. Then he put his shoulder to the cracked wood and the great outer doors of the Kasbah of El Glaoui swung open. Pigeons flew up out of the gloom.

I followed the guardian through a guano-scented gatehouse into a sloping courtyard. “La Place de la Danse,” he said. He pointed to a collapsed balcony hanging from an upper wall. “Here El Glaoui entertained his guests — film stars, royalty, Europeans — with music and dancers.” He crossed to a grilled window and pointed his torch down into the darkness. “And down here he entertained himself — torturing his prisoners in the dungeons.” He smiled. “He was a versatile man.”

The last inhabitant of this crumbling medieval castle — Si Hadj Thami el Glaoui, pasha of Marrakesh, caid of Telouet, Berber chief of the Merouara tribe, lord of the Atlas, viceroy of southern Morocco — lived in parallel universes. In 1953, he arrived in London on the boat train from Paris to attend the Queen’s coronation. He had been invited by a man with a weakness for tribal chieftains: Winston Churchill. Just months before, El Glaoui had ordered the severed heads of his enemies mounted atop the gates of his palace in Marrakesh.

Known as Dar el Glaoui, the palace is now a government ministry. There are beautiful courtyards and grand reception halls, but they lack the old frisson. Not given much to orgies or displaying severed heads, the Moroccan department of antiquities has brought a suburban respectability to the place.

I was staying in one of El Glaoui’s smaller properties, the Riyad Al Moussika, which has been restored and renovated as a guesthouse. In Marrakesh, you fall into riads the way Alice fell into Wonderland — a dusty alley, a windowless wall, a stout door, and then, suddenly, courtyards and blue pools, roses and exquisite tilework, orange trees and cushioned divans.

Over dinner, we discussed El Glaoui. He had been the staunch ally of the French, who armed and encouraged him while overlooking his excesses. His loyalty allowed him to become the virtual ruler of southern Morocco, and kingmaker to the whole country.

“He belonged to another world,” said Giovanni, our urbane host. “He was a Berber from the Atlas, a warlord, a mountain chieftain. To understand El Glaoui, you must go to the great kasbah at Telouet, to his mountain stronghold.”

ON THE road south across the Marrakesh plains, the traffic consisted of cyclists and donkey carts. Cowled figures stood in the shade of eucalyptus trees. Ahead, the mountains were ghostly behind veils of summer heat. After a time, the road began to twist and climb through hills, humpbacked as dinosaurs, their flanks clothed with cactus and Indian figs.

In the 1930s, keen to impress the visiting French resident-general, El Glaoui ordered this road lined with Berber tribesmen and women to salute the passing cavalcade, all the way to the Tizi-n-Tichka pass, some 40 miles distant. At the top of the pass, he assembled 10,000 mounted warriors, each of whom fired his rifle 20 times to welcome the visitor. The noise of this huge salute echoed off the surrounding mountains like thunderclaps. The hospitality at the evening banquet was on a simi-lar scale. Several hundred slaves roasted sheep in pit ovens, while the female dancers, like the warriors, were reckoned to number in their thousands.

Like most Atlas passes, the Tizi-n-Tichka is a spectacular and a colourful affair. Along the roadside, stalls sell the minerals that give the convoluted flanks of the mountains such vivid hues — dark burgundy, bands of yellow and vivid pink, violet, deep blues and cold mineral greens. Climbing torturously upwards, the road becomes a vulnerable thread among massive summits grained with colour. It is better not to look down.

Just beyond the top of the pass, three hours’ drive from Marrakesh, is the turning to Telouet. The road follows a high valley of wheat fields and orchards between bleak hills stained mineral red, as if some reflection of the bloody history of the area.

Twenty minutes later, the great kasbah appeared, set in a patchwork of irrigated fields and surrounded by the clustered houses of the village. From their flat roofs, it rose like an elaborate sand castle. Its enormous flanking walls, set with arched gateways, were crowned with towers and turrets and crenellated ramparts. It was vast, rambling and fantastical.

It was also ruinous. Wooden ribs protruded through the walls. The fluted chimneys looked like melted candles. Storks had colonised the ramparts, their giant nests in danger of toppling onto the heads of passing villagers below.

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