[Stanza 4]
And then at furious speed he rode
Along the Niger's bank;
His bridle-reins were golden chains,
And, with a martial clank,
At each leap he could feel his scabbard of steel
Smiting his stallion's flank.
[Stanza 5]
Before him, like a blood-red flag,
The bright flamingoes flew;
From morn till night he followed their flight,
O'er plains where the tamarind grew,
Till he saw the roofs of Caffre huts,
And the ocean rose to view.
[Stanza 6]
At night he heard the lion roar,
Caffre == Originally meaning “one of a race inhabiting Kafiristan in Central Asia” possibly from kafara “to be sceptical in religious matters; a name given to certain infidel races by the Mohammedans” it is now a pejorative term to describe a coloured person; synonymous with Kaffir in S. Africa and elsewhere 
 Source
The Slaves Dream