With the help of some courtiers of Kukawa, 'Abd ar-Rahman deposed his brother Umar in November 1853 and became Shehu of Borno. He was considered too violent and tyrannical by his followers which explains why he only reigned for ten months before his brother reconquered his throne in September 1854. He was then executed, most probably in December 1854.
'Abd ar-Rahman as seen by Heinrich Barth
In 1851, a British expion led by Heinrich Barth arrived in Borno. For Barth,'Abd ar-Rahman was a
good soldier but a man of very loose and violent character. When a youth he had committed all sorts of violence and injustice, carrying off young brides by force to indulge his passions; he was besides, a man of little intelligence. Being but a few months younger than Omar, he thought himself equally entitled to the succession; and if once admitted into a high position in the empire, he might be expected to abuse his influence on the very first opportunity