History: TestAS practice testlets

Magna Carta (Latin for "Great Charter") was granted by King John of England in June 1215 at Runnymede, near Windsor. John had lost most of his lands in France, raised heavy taxes to fund his wars and quarrelled with the Church, and a large group of barons, the most powerful landholders, had rebelled against him. The charter was a peace agreement in which the king promised to respect a long list of rights and customs, most of them concerning the barons, the Church and the city of London.

One of its clauses, often numbered 39, is quoted most frequently today. In a modern paraphrase, it says that no free man shall be arrested, imprisoned, deprived of his property, outlawed, exiled or otherwise ruined, nor shall the king proceed against him, except by the lawful judgement of his equals or by the law of the land. Another clause promised that justice would not be sold, denied or delayed.

In the short term, the charter failed. John had no intention of keeping it, and within a few weeks he asked Pope Innocent III to annul it, which the Pope did in August 1215. Civil war followed. After John's death in 1216, however, the government of his young son Henry III reissued a revised version, and further versions followed in 1217 and 1225. The 1225 charter became part of English law, and a few of its clauses remain in force today.

Over the following centuries, Magna Carta acquired a meaning far beyond its original purpose. In the seventeenth century, English lawyers opposed to the Stuart kings presented it as an ancient guarantee of the liberties of all Englishmen. American colonists later appealed to it, and it influenced the idea of due process in the United States Constitution. Today it is often cited as a founding document of the rule of law and human rights.

A historian analysing such a source asks what kind of document it is, who produced it and for whom, in what circumstances and for what purpose, and what it meant to its contemporaries. The historian must avoid anachronism, the error of reading later ideas into an earlier text. In 1215, "free man" excluded the majority of the population, the unfree peasants (villeins), who were bound to their lords.

Historians distinguish between different kinds of causes. Long-term causes are conditions that developed over years or decades and made an event possible or likely. Short-term causes are developments in the period immediately before the event. A trigger, or occasion, is the specific incident that set events in motion. Historians also ask which causes were necessary, meaning the event would not have happened without them, and whether the outcome was the result of deliberate decisions or of structures that limited what individuals could do.

The outbreak of the First World War in 1914 is a classic case. Among the long-term causes, historians name the system of alliances that divided Europe into two blocs, the Triple Alliance of Germany, Austria-Hungary and Italy and the Triple Entente of France, Russia and Britain; the arms race, especially the naval rivalry between Germany and Britain; imperial competition for colonies and influence; and nationalism, particularly in the Balkans, where the decline of Ottoman power left rival states and national movements. Military planning also mattered: Germany's Schlieffen Plan foresaw a rapid attack on France through Belgium before turning against Russia, which made it hard to limit any conflict involving Russia.

The trigger was the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife in Sarajevo on 28 June 1914 by Gavrilo Princip, a young Bosnian Serb nationalist. In the weeks that followed, the July Crisis, decisions in Vienna, Berlin, St Petersburg, Paris and London turned a regional conflict into a European war. Germany assured Austria-Hungary of its support; Austria-Hungary sent Serbia an ultimatum that was designed to be hard to accept; and mobilisations followed each other.

The question of responsibility has been debated ever since. The Treaty of Versailles of 1919 assigned responsibility to Germany and its allies. In the 1960s, the German historian Fritz Fischer argued that Germany's leaders had pursued far-reaching war aims and deliberately risked war. Others, such as Christopher Clark in The Sleepwalkers (2012), have emphasised that the leaders of several great powers contributed to a catastrophe that none of them fully foresaw.