1. The Battle Of Tours, 732
In the sixth century, the Muslim armies were a strong force, toppling great armies and claiming huge swaths of land. In the early sixth century, Berbers from Libya sailed into Spain claiming land for the Ummayad Dynasty. They took most of southern Spain, moving towards France. This was a serious attempt by the Muslims to take Western Europe and hadn't it been for Charles Martel, they would have likely succeeded.
Martel had led his armies to meet the Muslims. At first, they didn't get off to a good start and suffered several defeats. But when the Muslims got lazy, abandoning their posts, and started looting and pillaging local villages, Martel staged a last attempt and was able to turn the Muslims back to southern Spain. Had Martel's army been defeated, there would have been no other to stop the Muslims from entering Western Europe.
2. The Battle Of Tsushima, 1905
While it is not widely known, Japan and Russia had fought in an intense war before World War I over power in the region. This war, which saw a Japanese victory, would turn Japan into a key player during the second World War. The Russians had wanted control of Manchuria, as did the Japanese. Consequently, both met at Tsushima. This sea battle was also the first time electronic communication was used which resulted in an almost complete destruction of the Russian Navy as well as Japanese control over Manchuria.
3. The Battle Of The Metaurus, 207 B.C.
The Punic Wars were a series of wars between the world's greatest superpowers of the era, Rome and Carthage. In total, there were three wars, which were all won by Rome, albeit barely. The Battle of Metaurus was the smallest battle of the Second Punic Wars. Hannibal's brother, Hasdrubal, faced off against the Roman consul, Nero. Hasdrubal brought reinforcements so large that had he met up with Hannibal, Rome would have fallen. When Hasdrubal lost the battle, Nero had him beheaded and his head thrown into Hannibal's camp. The Romans would later defeat Hannibal.
4. The Battle Of Blenheim, 1704
Louis XIV wanted regional peace. But in order to achieve peace, he needed to knock out the Hapsburg capital. So he arranged a massive army and moved in on the superpower. Worried of losing, the Austrians allied with England, Rome and Prussia, forming a Great Alliance. The armies met at the town of Blenheim, where the English siege began. The French were able to hold off many repeated attempts to enter the city, but eventually, the English broke through. As a result, the French suffered huge losses, destroying their 'invincible' reputation, preventing them from being able to conquer all of Europe.
5. The Battle Of Hastings, 1066
During the eighth and ninth centuries, England had been isolated. Keeping to themselves on their own island meant that they could sit back and watch the rest of Europe tear itself to pieces. All this changed when the Normans decided that they did not like England hiding in the corner like that. They pushed to invade England with a large army, and at the battle of Hastings, they succeeded. This victory placed a foreign ruler on the English throne for the first time, and opened England to influence from many other countries. Nevertheless, this was the last time an army would successfully invade England.
6. The Battle Of Lechfeld, 955
Throughout the eight century, the Hungarian Empire was on the rise, wanting more and more land. Upon establishing themselves in the east, they made a move for Western Europe. At the Battle of Lechfeld, the Germans fought off the invasion, successfully defeating Hungarian invaders, keeping them from moving into Western Europe and effectively destroying any chance that the Hungarian Empire had of becoming a regional power player. This battle was also the first time the knights of a cavalry would win an important battle, setting the precedent for the rest of Western Europe to use cavalry instead of archers.
7. The Battle Of Emmaus, 166 B.C.
This battle took place when the Jewish forces were battling for control of Jerusalem. But this time, it had been the Greeks who had tried to invade Jerusalem. The Jewish forces tricked the invaders into thinking they had fled to the mountains, when in reality they were lying in wait for the Greeks to leave their camp. As soon as they did, the Judean soldiers ransacked their base camp. When the Greeks returned all of their supplies and weapons were taken. This victory ensured peace for Jerusalem and kept foreign invaders off their soil.
8. The Battle Of Pultowa, 1709
Sweden and Russia had fought in the 16th century to determine who would become the next great regional power player. At the time, it was Sweden which controlled most of northern Europe and was seeking to expand into Russia. But the Swedes didn't have the benefit of hindsight and attempted to attack in the winter. As they swept mightily into Russia, it didn't take the Russians long to get serious and bring their A-game to Poltava. The battle was quite bloody and both sides suffered a massive loss. When the dust settled, the Russians were victorious. The loss actually led to the Swedes losing their seat of power and Russia taking over.
9. The Battle Of Valmy, 1782
After the French Revolution, there were a number of revolutionary battles over French territory. Prussia brazenly attempted to conquer a weakened France, but they were met by French forces at Valmy. Despite coming out of a revolution with an unstable government structure and being outnumbered and outgunned, they defeated their opponents and forced the Prussians to retreat. As the country had just bounced back from a revolution, the army was made up of volunteers. Many see it as the first victory by an army inspired by liberty. The victory made the world take this new France seriously.
10. The Battle Of Yarmuk, 636
The success that Muslims achieved in the Middle East whereby they took land and overturned superpowers would not have been possible had they lost at Yarmuk. Yarmuk is a small town outside the Sea of Galilee between Syria and Palestine. At the time, the Arabs had controlled the East, while the Byzantine Emperor had control over the Levant - including Palestine, Syria, Lebanon and Jordan.
With the tactical genius of the Muslim leader Khalid bin Waleed, they retreated to the fields outside the city and waited for the Byzantines to approach them. Although they were calling the massive Byzantine army out into the open, Waleed was able to outsmart the Byzantines and destroy his opponents. The attack left the entire area, including the emperor's stronghold in Antioch, open to Arab attack. In the months that followed, the Arabs took over the Middle East and crippled the Byzantine Empire.