The meaning of the alliance system is when countries work together to achieve a common goal. this means that when a country is in need, the other countries help them out. this is why the Austria- hungary and Serbia war resulted into a general war involving many country.
Explanation:
The Hungarian empire declared war on the slavic country of Serbia following the assassination of a crown prince of the Austrian Hungarian empire by a serbian nationalist. This made the Slavic Russians that had an alliance with serbia to declare a war on the Austrian Hungarian Empire and mobilised their troops to defend serbia their ally.
Futhermore, Germans had alliance with Austria Hungarian Empire also declared a war on Russia. This made France and England to declare war on Germany because they had alliance with Russian. All these led to the general war that involved many countries.
He stopped the Muslim advance from Spain into France. was the impact did the Frankish leader Charles Martel have on Christian Europe's relations with Muslim Spain in the eighth century it took place in 732 at Poitiers.... Hope I could help