Under the Delimitation, Sudan's border with Abyssinia was contested by raiding tribesmen trading slaves, breaching boundaries of the law.  In 1905 Local chieftain Sultan Yambio reluctant to the end gave up the struggle with British forces that had occupied the Kordofan region, finally ending the lawlessness. The continued British administration of Sudan fuelled an increasingly strident nationalist backlash, with Egyptian nationalist leaders determined to force Britain to recognise a single independent union of Egypt and Sudan. With a formal end to Ottoman rule in 1914, Sir Reginald Wingate was sent that December to occupy Sudan as the new Military Governor. Hussein Kamel was declared Sultan of Egypt and Sudan, as was his brother and successor, Fuad I. They continued upon their insistence of a single Egyptian-Sudanese state even when the Sultanate of Egypt was retitled as the Kingdom of Egypt and Sudan, but it was Saad Zaghloul who continued to be frustrated in the ambitions until his death in 1927.