Bagirmi became known to Europe by the travels of Dixon Denham (1823), Heinrich Earth (1852), who was imprisoned by the Bagirmese for some time, Gustav Nachtigal (1872), and P. Matteucci and A. M. Massari (1881). The country in 1871 had been conquered by the sultan of Wadai, and about 1890 was over-run by Rabah Zobeir who subsequently removed farther west to Bornu. About this time French interest in the countries surrounding Lake Chad was aroused.