Born in India of missionary parents, Lugard was educated in England and, after briefly attending the Royal Military College at Sandhurst, joined the Norfolk Regiment. Posted to India and swept into the British imperial advance of the 1880s, he served in the Afghan, Suakin (Sudan), and Burma (Myanmar) campaigns. An officer with a promising career ahead of him in British India, he experienced a catastrophic love affair with a married woman. Highly strung and undermined by Burma fever, he sought oblivion by following the explorer David Livingstone's lead in fighting Arab slave raiders in eastern Africa. In 1888 he was severely wounded while leading an attack upon a slaver's stockade near Lake Nyasa. But he had found his life's work in service for Africa and for Britain—work that he saw as having a mutually beneficial purpose.

His next enterprise was under the imperial British East Africa Company, one of the chartered companies that preceded imperial annexation in Africa. Leaving Mombasa in August 1890, he led a caravan for five months along an almost untrodden route of 800 miles (1,300 km) to the advanced kingdom of Buganda. Here he found a complex struggle going on among animists, Muslims, Protestants, and Roman Catholics—the latter two groups converted by British and French missionaries who had reached Buganda earlier by a southern route—and the nominal king, or kabaka. Within 18 months—not without a brief use of his one operative Maxim gun—Lugard imposed peace, carried out an immense march to the west, and won a treaty of allegiance from the kabaka. Hearing that his company meant to abandon Uganda because of mounting expenses, he hurriedly returned to England to fight a successful two-pronged campaign to defend, first, the retention of Uganda in addition to imperial annexation and, second, his own reputation against accusations of harshness and injustice.

In 1894–95 Lugard accepted another dangerous mission, this time for the Royal Niger Company, to race the French in a treaty-making exploration on the Middle Niger. He succeeded in that enterprise in spite of great hardships—including a poisoned arrow in his head. From the Niger he went, again at some risk to his life, to the semidesert of the Bechuanaland Protectorate for the private British West Charterland Company, which was prospecting for diamonds. There he was tracked down by a runner sent by the colonial secretary, Joseph Chamberlain, to offer him his first official government appointment. He was to create a British-officered African regiment that he was to employ in a second attempt to fend off the French, who then were competing with the British right across Africa from the Niger to the Nile. This was to become the famous West African Frontier Force. Lugard's success in this difficult undertaking led to his appointment as high commissioner for Northern Nigeria.

Most of this vast region of 300,000 square miles (800,000 square km) was still unoccupied and even unexplored by Europeans. In the south were pagan tribes and in the north, historic Muslim city-states with large walled cities whose emirs raided the tribal territories to the south for slaves. In three years, by diplomacy or the swift use of his small force, Lugard established British control, though in hastening to take the major states of Kano and Sokoto he forced the hands of his more cautious home government. Only two serious local revolts marred the widespread acceptance and cooperation that Lugard obtained. His policy was to support the native states and chieftainships, their laws and their courts, forbidding slave raiding and cruel punishments and exercising control centrally through the native rulers. This system, cooperative in spirit and economical in staff and expense, he elaborated on in his detailed political memorandums. It greatly influenced British administration in Africa and beyond. Though sometimes misapplied or overprolonged, it helped bridge the gap between tribal systems and the new movements toward democracy and unity. Lugard's main fault as an administrator was an unwillingness to delegate responsibility, but the variety of the conditions and the vast distances acted as a check on this fault. If some of his officers were critical, the majority greatly respected their chief, and a number of “Lugard's men” went on to govern other territories in Africa.

In 1902 Lugard married Flora Shaw, a beautiful and famous woman, herself a great traveler, an authority upon colonial policy, and a member of the staff of The Times of London. A very deep devotion and partnership grew up between them. Because she could not stand the Nigerian climate, Lugard felt obliged to leave Africa and to accept the governorship of Hong Kong, which he held from 1907 to 1912. No greater contrast could be imagined than that between the vast untamed expanse of Northern Nigeria and the small island of Hong Kong with its highly civilized Chinese and sophisticated commercial British community. But the bushwhacker from Africa achieved a surprising degree of success and, on his own initiative, founded the University of Hong Kong.

He could not, however, resist the great opportunity offered to him in 1912 to unite the two parts of Nigeria into one vast state. The south and north showed wide contrasts in their original character and in their traditions of British rule. It was an immense task to unify their administration. Lugard did not attempt a complete fusion of their systems and retained a degree of dualism between south and north. He found the south, especially the sophisticated Africans of Lagos and the southeast, less easy to understand than the northerners, and in 1918 he had to deal with a serious outbreak in the important city-state of Abeokuta. Nor did he find it easy to extend the principles of indirect rule to the loosely organized societies of the Igbo (Ibo) and other southeastern tribes. His tenure of office also was made more difficult by World War I, with its interruption of communications, its resultant shortages of staff, and the war with the Germans in the Cameroons along his eastern frontier. Yet, in the main, Lugard carried through an immense task of unification, which was officially declared on Jan. 1, 1914. Historians must judge the event by the decision of the Nigerians to obtain their independence in 1960 as a united state and to defend it against the attempted Igbo secession to set up an independent state, Biafra, in the late 1960s.

In 1919 he retired, but only to a life of unceasing activity in his role as the leading authority on colonial government. He wrote his classic Dual Mandate in British Tropical Africa, published in 1922. In 1928 he became Baron Lugard of Abinger and spoke with authority in the House of Lords on colonial subjects. He became British member of the Permanent Mandates Commission and of the International Committees on Slavery and Forced Labour and chairman of the International Institute of African Languages and Cultures. To the end of his life, deeply saddened by the death of his wife in 1929, he worked almost incessantly in his secluded house on a survey of matters affecting the interests of native races both inside and outside the British Empire.

Though to modern critics of colonialism there may seem much to criticize in his ideas and actions, there can be no questioning the great range and effectiveness of the three periods of his work: in the opening up of Africa; in its government at a most formative stage in its history; and as elder statesman working during his so-called retirement almost up to his death.