 In the year which followed, the prince gave evidence of considerable military and diplomatic ability.He rallied the Bulgarian army, now deprived of its Russian officers withdrawn by Tsar Alexander III which Alexander replaced by graduates of the Bulgarian Military Academy to resist the Serbian invasion (later on called "The Victory of Bulgarian Cadets vs. Serbian Generals").The Bulgarians won a decisive victory at Slivnitsa (19 November), which Alexander had little to do with, having arrived in after the battle was already over.