FRENCH COLONIAL EXPANSION 143 
and Mangin, which had come from Kong to the north- 
western part of the Ivory Coast colony by way of Touba. 
Thus was established effective connection between the 
three protectorates, the Sudan, Guinea. and the Ivory 
Coast. 
The union of all the French colonial possessions in Africa 
was now accomplished; yet four things remained to be done 
before this union could be said to be permanent and com- 
plete: the complete pacification of the Upper Congo; the 
subjugation of Mauretania, making connection between the 
Senegal and Algeria possible; the extension of the French 
control over the Algerian hinterland and the central Sahara; 
and the establishment of proper means of communication 
and transport between the various parts of this colonial 
empire. The first of these was speedily accomplished, dur- 
ing the years 1899-1901, through the capture of Dikoa and 
the subjugation of the kingdom of Rabah, by Commandant 
Lamy and Captain Dangeville with the combined forces of 
the three missions. 
Several attempts were made to penetrate the western 
Sahara, notably by M. Soleillet in 1880, by Camille Douls 
in 1887, and by Fabert between 1889 and 1893; but a suc- 
cessful connection of these territories with the other French 
protectorates was not accomplished until Paul Blanchet 
reached Atar, the capital of Adrar (T-Marr), in 1900. On 
June 27, 1900, the Sebkha d’Idjil was added in a delimita- 
tion treaty with Spain. In the two years that followed, the 
French power was firmly established in the northern portion; 
and in 1903 the districts of Trarza and Brakna, just north 
of Senegal, were taken over. Finally, the whole region was 
formed into the Territory of Mauretania and governed by a 
commissioner. 
During the years 1859 to 1861, Henri Duveyrier exe- 
cuted a series of remarkable explorations covering nearly