Illustration from The Life and Times of Queen Victoria published circa 1901.
Info from wiki: Kitchener was anxious to occupy Omdurman before the remaining Mahdist forces could withdraw there. He advanced his army on the city, arranging them in separate columns for the attack. The British light cavalry regiment, the 21st Lancers, was sent ahead to clear the plain to Omdurman. They had a tough time of it. The 400-strong regiment attacked what they thought were only a few hundred dervishes, but in fact there were 2,500 infantry hidden behind them in a depression. After a fierce clash, the Lancers drove them back (resulting in three Victoria Crosses being awarded to Lancers who helped rescue wounded comrades). One of the participants of this fight was Lieutenant Winston Churchill.