Why was the treat of Versailles placed upon Germany? I understand they lost the war but why was it so harsh? I've seen quite a few WW2 and WW1 documentaries and they always say it was a harsh treaty but never say why... Was Germany ultimately blamed for the cause of WW1? Did Austria-Hungry have similar restrictions placed upon them? What about the Ottomans? What type of war reparations were placed on Turkey? I understand there was global consequences for the England, loss of their empire, was this a reason?
The Treaty of Versailles was no where near as harsh as it is commonly depicted. It's true that everybody was engaged in an arms race for an eventual war, but Germany was by far the most gung-ho in their desire to go to war.
A huge motivation for Germany's hawkish nature was that Germany unified far too late in the game (only after the Franco-Prussian War in 1870). By the time they established the German Empire, the colonial powers of Britain and France had divvied up India, Indochina, parts of Africa (which would give them logistical centers that enabled their armies to quickly colonize the rest of Africa in the Scramble for Africa) and even spheres of influence in China. Russia colonized Siberia and brought in Central Asia into its sphere of influence. America, with the establishment of the Monroe Doctrine decades earlier, made its intentions known that South America would be brought into their sphere of influence with no interference from the European powers. As a result, Germany was geographically limited in terms of its expansion.
Another large problem for Germany was that it cornered itself into a dire situation in the Berlin Congress when it gave large concessions towards Austria-Hungary after the Russo-Turkish War of 1875. This was Bismark's attempt to mitigate Russia's growing influence in the Balkans, as the original terms for the end of the war gave Russia a Bulgarian vassal state that encompassed almost a third of the Balkan peninsula. Russia, though, was allied to Germany at the time, along with Austria-Hungary. Bismark decided to give Bosnia and Sandzak (an ethnic-Serb populated region that lied between Montenegro and Serbia) to Austria-Hungary because he deemed Austria-Hungary to be too incompetent to take advantage of their gains and subsequently increase their military might. This eventually backfired on Bismark, though, as Russia was so incensed by his betrayal at the Berlin Congress that they chose to realign themselves with France, the mortal enemy of Germany. France had been seeking to reconquer Alsace-Lorraine from Germany since the humiliating defeat in the Franco-Prussian War of 1870. Although their desire to reconquer Alsace-Lorraine has been characterized at times by the concept of Revanchism ("Revenge"), it was much more economical in nature. Alsace-Lorraine was an incredibly densely-populated region as well as highly industrialized. The economic output and the manpower reserves from the region were a significant boost to France. Another incredibly important part of Alsace-Lorraine was that it was the only region in France that reliably produced high amounts of iron (and thus, steel), an absolutely essential resource for industrialization. In the end, Germany was caught in between France and Russia with an increasingly fragile and frankly incompetent Austria-Hungary as their only reliable ally. Therefore, if Austria-Hungary desired to go to war, the German government felt shackled to tag along with them for fear of losing their only ally.
This brings me to the start of World War I. The Archduke had been assassinated by an ethnic Serb of Bosnia, an Austrian region at the time. There were tenuous ties to the Serbian government, which gave Austria a casus belli to invade Serbia. There's a common trope that secret alliances brought Europe into WWI, but Russia had proclaimed itself as protector of Orthodox Slavs since before the onset of the Crimean War. In addition, Serbia just 10 years earlier had a violent coup in which the Austrian-friendly Obrenovic dynasty had been overthrown by the Karadjordjevic dynasty. The Karadjordjevic family were known Russophiles and quickly aligned themselves with the Czar. It came to a surprise to no one that Russia came to Serbia's aid when Austria declared war. In fact, Austria were hesitant at first to declare war on Serbia because they distinctly knew that Russia would come to Serbia's aid. It was at the behest of the German chancellor that Austria chose to invade Serbia when he infamously gave Austria the carte blanche.
Now in regards to Austria-Hungary and the Ottomans after the war, they were given far harsher terms. Czechoslovakia, Hungary, Transylvania, Vojvodina, Croatia, Bosnia, Slovenia, and parts of what is modern-day Italy were all taken from the Austrians and given to either newly created countries or given to Italy. Hungary was especially hit hard: only 25% of the original Kingdom of Hungary was retained as Hungary, and more than 50% of ethnic Magyars were left out of the newly created Hungarian state. The Ottoman Empire had its Arab holdings forcibly taken from them by the French and the English. The state plunged into a civil war in which the empire crumbled and a new Republic of Turkey formed. Even then, Turkey was forced to fight a protracted war against the Entente in order to maintain its territorial integrity. Even the small state of Bulgaria had lost its Thracian possessions and parts of what is now Southern Serbia. The Thracian lands were especially important, as it meant Bulgaria had lost its direct access to the Mediterranean Sea.
Germany, in contrast, lost Alsace-Lorraine and the Polish-inhabited lands of Eastern Germany. Germany still maintained their territorial integrity, which is polar opposite to its allies.
When it comes to war reparations, it was seen as very reasonable for the time. What one has to realize was that Germany invaded France and fought the entirety of the war in the west on French territory. The Germans had ransacked Northern France, leaving it completely devastated after four years. As soon as the French and British pushed the Germans back to the border of Germany, they capitulated. As a result, the actual German land had been left untouched by the war. Therefore, it seemed justified by the French that they force the Germans to pay for the damages they inflicted upon French land.
What did not help the German cause was Germany's handling of Russia's surrender in 1917. The Treaty of Brest-Litovsk had far harsher provisions for Russia than the Treaty of Versailles. Russia gave up an entire half of their European possessions, including Ukraine, which was the breadbasket of Russia as well as their biggest supplier of coal and iron.
As for your question about England and their loss of their empire, this happened due to World War II, not World War I. The Germans pulverized British infrastructure in the Bombing of Britain, and England's desperation to stay in the war led it to incur massive loans from the US to pay for the war effort. In addition, this would be the second war in 20 years in which the English would suffer massive casualties. This led to an extremely economically crippled post-war England that could not hold onto their colonial possessions and were frankly exhausted from two massive wars.