1808) the kingdom
began to be harassed by the Fula, who had already conquered the Hausa
country. Expelled from his capital by the invaders, Ahmed was only
restored by the assistance of the fakir Mahommed al-Amin al-Kanemi, who,
pretending to a celestial mission, hoisted the green flag of the
Prophet, and undertook the deliverance of his country. The Fula appear
to have been taken by surprise, and were in ten months driven completely
out of Bornu. The conqueror invested the nearest heir of the ancient
kings with all the appearance of sovereignty--reserving for himself,
however, under the title of sheik, all its reality. The court of the
sultan (_shehu_) was established at New Bornu, or Birni, which was made
the capital, the old city having been destroyed during the Fula
invasion; while the sheik, in military state, took up his residence at
the new city of Kuka. Fairly established, he ruled the country with a
rod of iron, and at the same time inspired his subjects with a
superstitious notion of his sanctity. His zeal was peculiarly directed
against moral or religious offences. The most frivolous faults of women,
as talking too loud, and walking in the street unveiled, rendered the
offender liable to public indictment, while graver errors were visited
with the most ignominious punishments, and often with death itself.
Kanemi died in 1835, and was succeeded by his son, Sheik Omar, who
altogether abolished the nominal kingship of the Sefuwa.

During Omar's reign, which lasted about fifty years, Bornu was visited
by many Europeans, who reached it via Tripoli and the Sahara. The first
to enter the country were Walter Oudney, Hugh Clapperton and Dixon
Denham (1823). They were followed in 1851-1855 by Heinrich Barth. Later
travellers included Gerhard Rohlfs (1866) and Gustav Nachtigal. All
these travellers were well received by the Kanuri, whose power from the
middle of the 19th century began to decay. This was foreseen by Barth;
and Nachtigal, who in 1870 conveyed presents sent by King William of
Prussia, in acknowledgment of the sheik's kindness to many German
explorers, writes thus in December 1872:

"The rapid declension of Bornu is an undeniable and lamentable fact.
It is taking place with increasing rapidity, and the boundless
weakness of Sheik Omar--otherwise so worthy and brave a man--must bear
almost all the blame. His sons and ministers plunder the provinces in
an almost unheard-of manner; trade and intercou