Wilfrid Thesiger set out on his last journey into the interior of Oman in January 1950. He started from Muwaiqi’, in the Buraimi oasis, where Shaikh Zayid ibn Sultan, Shakhbut's younger brother and wali in the oasis, had his headquarters. Thesgier's plan was to make his way through Al Bu Shamis territory to the central steppes and then, provided the Duru’ did not bar his way, to cross the steppes to the Wadi Amairi before turning north with the aim of reaching Nizwa, Bahlah, Jabrin, and the other towns lying under the shadow of the Jabal Akhdar. (see Map 25) Apart from his own desire to penetrate to the very heart of Oman, Thesiger was also conducting a discreet reconnaissance on behalf of Iraq Petroleum to find out more about the current politics of inner Oman, perhaps even, to talk to the imam , Muhammad ibn ‘‘Abdullah al-Khalili, himself. For this reason Thesiger had decided, with the concurrence of the Foreign Office, to keep his journey secret from the sultan, Said ibn Taimur. If the latter knew about it, Thesiger was convinced, he would certainly forbid it, particularly if Thesiger intended to start from sultanate territory. But as Thesiger was making his approach from Trucial Oman, he could do nothing to prevent it; and in any case he had no power to intervene in the territories through which the explorer was to travel.

Thesiger left Muwaiqi’ on 12 January, with a party of ten Badu, including his three faithful Rashid, Salim ibn Kabina, Salim ibn Ghabaisha and Muhammad ibn Kalut, and four Duru’ of the Mahamid section led by Shaikh Huwaishal ibn ‘Ali, whom Shaikh Zayid had arranged should act as an escort. The crossing of the Duru’ country proved arduous and dangerous. Thesiger and his party were held up on the Wadi Sauhar by a strong force of Duru’ of the Muqairida section who refused to let them pass. Thesiger sent Huwaishil ibn ‘Ali ahead to make contact with the taminah of the Duru’, Ali ibn Hilal, who was encamped in the Wadi al-Aswad. Before Huwaishal returned Thesiger had been forced to retreat westwards into the Rabadh under threat of death from the Muqairida. He eventually came up with ‘Ali bin Hilal in the Wadi al ‘Ain in the middle of February, and from there he turned north and made his way up the wadi to the low-lying broken range of the Hamra Duru’.