The current country of Spain was divided into two primary kingdoms, Aragon and Castile, each led by a separate family. As was common during this time, a marriage was planned to unify the two kingdoms and make each more powerful than before. The two were married in 1469 when they were both still heirs to their respective thrones. After the marriage each inherited their own throne shortly after and the kingdoms were brought together. Of course this marriage did not completely unify the kingdoms and each continued to be ruled much as it had before, with its own officials, customs, and laws. This marriage did lead to the official unification later on and it made Ferdinand and Isabella two of the most powerful monarchs in Europe, where they were known for wielding their power to defend the Catholic faith. 

A Fyrd was an early English standing national army, commanded by its king. This is important to know because at the time few other countries were even unified. Much less having their own standing national army. England was setting the trend for how European countries would operate through the medieval era. 

Anne of Cleves survived marriage to Henry VIII because the two almost immediately realized they were incompatible. Anne granted Henry a divorce, became the king's sister and lived her life in riches and high esteem. Katherine Parr was lucky number six and outlived Henry so she too survived.

Queen Elizabeth I gave a famous speech at Tilbury after the defeat of the Spanish Armada. All throughout her reign Elizabeth had issues with her advisors, parliament, and people because of her gender. Though she was one of England's and the Tudor's most successful rulers, her reign was not without it challenges. One of the greatest came at the end of her reign when King Phillip of Spain attacked with his famous Spanish armada. This quote came from Queen Elizabeth I's final great speech to her people after a great triumph. 

Elizabeth I had her cousin the queen of Scotland, Queen Mary beheaded after years of imprisonment. Mary Queen of Scots represented a threat on multiple fronts; not only was she younger, beautiful, had a legitimate male heir, and was a catholic. Mary also had a legitimate claim to the thrown as a legitimate descendant of Henry VII. Elizabeth's legitimacy was questionable due to the nature of her parents' marriage.

Niccolo Machiavelli's 1513 treatise The Prince described how a ruler should maintain political power. Prior to Machiavelli, political theory typically described how rulers ought to rule based on specific moral and Christian principles. In The Prince, Machiavelli instead advocates for a more realistic mode of governance not restricted by such lofty concerns.

Quotation adapted from The Prince by Niccolo Machiavelli (1513; trans. Mariott 1908)

The Chartist movement gained its name from the People's Charter of 1838, which was a large-scale petition effort that found particular success among the burgeoning working classes of Britain's expanding industrial cities. The Chartists fought for Parliamentary reform, as they believed that the previous century's reforms did not go far enough. The Charter contained six specific points about Parliamentary elections: universal male suffrage, a secret ballot, no property requirements for members of parliament, equal parliamentary constituencies, and annual parliamentary elections.

The quotation reflects the central tenet of utilitarianism, the core philosophy of the extremely influential British thinker and social reformer Jeremy Bentham. Bentham’s philosophy holds that society, and by extension government, should work towards providing the greatest happiness for the greatest number of people possible. This is the core component of Bentham’s leading philosophy, utilitarianism. Bentham was considered a radical in his time; he advocated for, among other things, economic liberty, individualism, equal rights for women, the abolition of slavery, decriminalization of homosexuality, animal rights, and extensive social welfare.

Quotation adapted from Fragment on Government by Jeramy Bentham (1776)

Marxist history is based on the belief that history is one constant struggle between the economic classes. Marxist history considers factors like nationality, religious affiliation, ethnicity, and so on to be secondary to the competition between the classes, particularly the competition between the producers (the working class), the consumers (the middle class), and the owners (the upper class). It is based on the writings of Karl Marx.

Social Darwinism was an interpretation of the theory of natural selection that emerged in the second half of the nineteenth century. Social Darwinism essentially maintains that in human populations, just like in animal populations, natural selection is at work and only the fittest, smartest, and strongest will survive. It provided a convenient excuse for the abuses committed during the New Imperialism era, as it allowed European intellectuals to claim "natural superiority" over other races and defend their otherwise morally reprehensible actions. Of course, Social Darwinism was not universally propounded in this time period, but in the years since, it has come to be widely associated with Herbert Spencer. Spencer was one of the most famous philosophers of his time and an ardent believer in the benefits of competition.