Battle of Otavi The Battle of Otavi fought between the militaries of the Union of South Africa and German Southwest Africa on 1 July 1915 was the final battle of the South - West Africa Campaign of World War I . The battle , fought between Otavi mountain and Otavifontein , was a delaying action led by the German Major Hermann Ritter . Ritter ' s forces intended to buy the main German force at Tsombe several days so as they could harden their positions there . In the end , Botha ' s forces were able to rout Ritter ' s troops , leading to an overall breakdown in the German lines that brought the campaign to an end . Background . By mid 1915 the South African advance in German Southwest Africa had gained considerable ground and efforts at negotiating a ceasefire had failed . Rather than seek a decisive battle , the German commander Victor Franke had decided to resort to keeping his army as intact as possible so as to maintain a German claim to the territory after the end of the war . Rather than resort to guerrilla warfare or attempt to break out of German Southwest Africa , Franke decided to retreat along the railway and build up defenses around Tsombe . With the South African army under Louis Botha rapidly approaching , Franke decided to leave a delaying force under his second in command Major Hermann Ritter at Otavifontein . The delaying force was tasked with holding up Botha for as long as possible so that the main force at Tsombe could concentrate its forces and solidify its defenses there . Botha began his advance on June 18 , learning from intercepted communications that the Germans were retreating up the railway but would not retreat farther than Namutoni . Botha split his 13 , 000 troops into four columns with one on each flank and two under his personal command driving up along the railway . With a swift advance , the South Africans began to surround the German positions and Botha ' s central columns managed to reach Otavi by July 1 . The Germans thought that Botha ' s advance would be hampered by a lack of water and rough terrain , and were ill prepared for the looming South African attack . At his disposal Botha had 3 , 500 cavalry compared to Ritter ' s 1 , 000 infantry and ten machine guns . Although heavily outnumbered , Ritter ' s forces did have the advantage of the high ground , as the territory they defended was quite mountainous . Despite this advantage , Ritter feared that his force would become surrounded and spread his forces out to lengthen his line of defense . Battle . Because Ritter ' s line of defense was so long , his flanks were unable to support each other . That , combined with his lack of forces to man such a wide perimeter adequately , caused his left flank to falter when the South African forces advanced upon it . Fearful his lines would break , Ritter pulled back to the hills of Otavifontein and to Otavi mountain . Despite the fact that these new positions held the high ground , the Germans had not prepared any fortifications there . With no artillery and no solid defensive positions , the German force easily broke into a general retreat when pressed by Botha ' s troops . By 1pm the battle had ended , with Ritter pulling back to positions near Gaub and leaving Botha with a clear path to the main German body at Tsombe . Aftermath . Botha ' s victory was swift , with the South African advance being delayed only a day and suffering only four dead and seven wounded . The Germans had fled without putting up any committed defense , and Ritter ' s force fled largely intact with only three dead , eight wounded , and twenty captured . Although a delay of just two days by Ritter would have sufficed , Ritter ' s early withdrawal allowed Franke ' s unprepared forces to become nearly encirled . With no means of escaping further up the rail line and a general lack of will to pursue any other course of action , Franke had little choice but to surrender his forces to Botha on July 9 , effectively ending all major German resistance in Southwest - Africa .