World History, Global History or Transnational history (not to be confused with Diplomatic or International History) is a field of historical study that emerged as a distinct academic field in the 1980s. It examines history from a global perspective. It is not to be confused with comparative history, which like world history, deals with the history of multiple cultures and nations, but does not do so on a global scale.

World History looks for common patterns that emerge across all cultures. World historians use a thematic approach, with two major focal points: integration (how processes of world history have drawn people of the world together) and difference (how patterns of world history reveal the diversity of the human experience).

The study of world history is in some ways a product of the current period of accelerated globalization.

The advent of World History as a distinct field of study can be traced to 1980s, and was heralded by the creation of the World History Association and of graduate programs at a handful of universities. Over the past 20 years, scholarly publications, professional and academic organizations, and graduate programs in World History have proliferated, although the WHA is still predominantly an American phenomenon. It has become an increasingly popular approach to teaching history in American high schools and colleges. Many new textbooks are being published with a World History approach.

World War I (WWI), which was predominantly called the World War or the Great War from its occurrence until 1939 (World War II), and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. It involved all the world's great powers, which were assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom, France and Russia) and the Central Powers (originally centred around the Triple Alliance of Germany, Austria-Hungary and Italy; but, as Austria–Hungary had taken the offensive against the agreement, Italy did not enter into the war). These alliances both reorganised (Italy fought for the Allies), and expanded as more nations entered the war. Ultimately more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. More than 9 million combatants were killed, largely because of enormous increases in lethality of weapons, thanks to new technology, without corresponding improvements in protection or mobility. It was the sixth-deadliest conflict in world history, subsequently paving the way for various political changes such as revolutions in the nations involved.

Alexander III of Macedon (20/21 July 356 – 10/11 June 323 BC), commonly known as Alexander the Great (Greek: Ἀλέξανδρος ὁ Μέγας, Aléxandros ho Mégas from the Greek αλέξω alexo "to defend, help" + ανήρ aner "man"), was a king of Macedon, a state in northern ancient Greece. Born in Pella in 356 BC, Alexander was tutored by Aristotle until the age of 16. By the age of thirty, he had created one of the largest empires of the ancient world, stretching from the Ionian Sea to the Himalayas. He was undefeated in battle and is considered one of history's most successful commanders.

Alexander succeeded his father, Philip II of Macedon, to the throne in 336 BC after Philip was assassinated. Upon Philip's death, Alexander inherited a strong kingdom and an experienced army. He was awarded the generalship of Greece and used this authority to launch his father's military expansion plans. In 334 BC, he invaded Persian-ruled Asia Minor and began a series of campaigns that lasted ten years. Alexander broke the power of Persia in a series of decisive battles, most notably the battles of Issus and Gaugamela. He subsequently overthrew the Persian King Darius III and conquered the entirety of the Persian Empire. At that point, his empire stretched from the Adriatic Sea to the Indus River.