The rather absurdly named 'Middle Ages' [in the middle of what exactly?], from 500 AD to 1500; was a time of vigour, invention, warfare, self-defence, expansion, growing literacy, productivity, and slowly, a better life. Europe's population grew from some 30 millions when Rome mutated [to use a favourite Atheist term]; from a Latin based empire into 3 Germanic kingdoms.
The Middle Ages were not romantic, easy, rosy, nor an era of dancing-happy-grinning-sad-deluded-self flagellating superstition. Life in its daily grind rarely imitates art. It was a hard existence. But thanks be to god, that Europe survived and thrived. If it had faltered, there is no modern world.
The High Middle Ages: 1100-1300
The era from 1000 AD to 1100 is the really the platform for science and the modern world world [see here near the end]. Ancient Greek and Roman science such as it was, literature, ideas and culture were well known to the post-Roman empire Europeans [see here]. After the Moslem irruptions and destruction of Christianity from Syria to Southern France; the closing off of trade, the endless Jihads, piracy and attacks on Christianity, a person possessing some common-sense would assume that life, liberty, literacy, and science would all suffer. And so they did. But the base platform for the European renaissances [plural] was always in place.
It was only in Europe that the faux-theories of Aristotle were overturned [they were accepted in-toto by Moslem 'scientists, see here]; and real science developed. This was due to the Christian faith and the need given this ideological framework; to search for truth in order to understand the perfection of the God's natural world order.
As the Moslem grip on the Mediterranean world was at first stayed; then rolled back, ideas, cultural exchange, trade and from trade; prosperity increased. This is again only common-sense. From 1095 onwards we have the 200 years of the Crusades in the Holy Land. This necessary war for survival occupied the Moslem Jihad in the heart of their occupied territories. It gave Europe 200 years to acquire, assimilate, build upon, and extend Eastern influences.
So what did European Christian civilization achieve between 1100-1300 ? Not only were pagans from the north and east Christianized and the endless exogenous terror of Islam finally arrested; but a long list of creations from 3-D art to the wheelbarrow, from universities to astronomical calculations, were developed. Most vitally Aristotle by 1300 was thoroughly discredited and the conceptions of Aristotleian theology including; geocentricity, an immobile cosmos, and 'laws' or in modern parlance 'settled science' such as life-from-dead-matter [abiogenesis]; or an immobile earth, were dispatched.
-1100 Ptolemy's 'Almagest' or compendium of ancient astronomy is translated and analyzed.
-1150 or so, Hindu numerals arrive and begin to modify mathematics, science and commerce.
-Gerard of Cremona (1114-1187) authored seventy translations of various Moslem-Arabic works including Avicenna's medical encyclopedia, itself just a restatement of Galen's 'medical advice' [much of which was of course quite wrong and even insidious].
-The astrolabe, an astronomical calculator invented by the ancient Greeks, reappears in Europe by 1200. It helps push astronomy to new mathematical and scientific truths and achievements.
-By 1200 Euclid's geometry had been through six translations from its original Greek.
-Chinese paper manufacture arrives in Europe by 1200 and the process is immediately seized and improved upon.
-The trebuchet, a counterweight catapult which probably originated in China, is either independently discovered in France; or built using a Chinese model circa 1100.
-The compass, traditionally attributed to China, but perhaps of Byzantine origination, is used by Europeans to transform shipping and maritime warfare.
-Windmills as a power source are developed independently in Europe before 1100.
-Water mills, necessary for food production, are built in their thousands, from 600 to 1200 AD.
-A long litany of agricultural inventions occur, including brewing, crop rotations, the iron plough, the use of the horse; the horse-collar; the horse-shoe; the industrial production of iron farm implements; and new varieties of grains and seeds.
-Gunpowder is imported from China and by 1304 is adapted for military usage.
-Europeans discover the manufacture of linen circa 1100 [or rediscover since the Hebrews had produced linen ]. This greatly reduces the price of cloth and clothing.
-Used linen is recycled into paper, circa 1200.
-The accumulation of paper laid the foundation for the printing press.
-Europeans develop the world's first mechanical clocks and the most accurate water clocks between 1100-1300.
-Christian scholastics [see here], analyzed, synthesized [see Aquinas for eg.]; and slowly refuted or amended Aristotleian dogma. This is was the crucial edification for real science to take place.
-Roman Law was 'rediscovered' at the University of Bologna [in particular], a crucial development for both Church canonical law; and secular rule and order [the negative of this development was that ancient Roman law institutionalized torture of course.....but didn't the 'Enlightenment' embrace all of 'classical civilization' .....?]
-Innovations in art, design, architecture, literature, including the establishment of vernacular languages flood into society and the culture at large. Giotto, Dante, Seger, the Romanesque, the Gothic, Chaucer and a host of others now appear as innovators and not just imitators of the 'classical age'. Europeans were far ahead of both classical antiquity and the rest of the world by 1200.
Why this effusion of creativity genius which only occurred in Catholic, Christian Europe ? The reasons are as obvious as they are never illumined, discussed, or taught. The Christian-world view is a complicated framework but there are some elements which can be discerned to give it a decided superiority over other belief systems, including modern Atheism-Darwinism, or modern Secularism-Humanism [another absurd word for Marxist].
The Christian belief system knows that:
Nature is not managed by supernatural, capricious forces.
Natural physical laws do exist, which are immutable, inviolate and in need of investigation and comprehension.
There is only one correct approach to unify philosophy or metaphysics with reality and physics.
In this world-view, the Christian knows that nature is not something to be sacrilized, but simply understood, and within reason, used for the betterment of mankind. Rocks, trees, streams, storms and flowers are not inhabited by deities; nor do they lie beyond our power to either comprehend what they are; or to utilize them for what they are. Importantly, the Christian framework was not, and should not be 'relative'. Islam is not as 'relatively' advanced, moral or the same as Christianity for example. It is decidedly inferior, vicious, pagan, misogynist, suffused with violence and immoral ignorance. Nazism is not 'relatively' as acceptable as pluralist democracy; nor is Chinghis Khan's sky-god as reasonable as Christ. In other words 'relativity' does not exist, except perhaps in calculations of space and time.