During the 20th century BC the Indo-European Hittites entered the region and gradually established a great empire which was destroyed by invaders in the 12th century.

During the late 19th and early 20th centuries, physicists discovered subatomic components and structure inside the atom, thereby demonstrating that the ' atom ' was divisible.

During this period winter sports were slowly introduced: in 1882 the first figure skating championship was held in St. Moritz, and downhill skiing became a trendy sport with English visitors early in the 20th century, as the first ski-lift was installed in 1908 above Grindelwald.

During the turn of the 20th century British Israelites carried out some excavations of the Hill of Tara in Ireland looking for the Ark of the Covenant – the Royal Society of Antiquaries of Ireland campaigned successfully to have them stopped before they destroyed the hill.

During the early 20th century, Alicante was a minor capital that enjoyed the benefit of Spain's neutrality during World War I, and that provided new opportunities for the local industry and agriculture.

During the 20th century communications used flags, morse code by radio, line and lights, voice and teleprinter by line.

During the 20th century the Plateau tribes, such as the Nez Perce perfected contour-style beadwork, in which the lines of beads are stitch to emphasize the pictorial imagery.

During the 20th century White Notes were issued in denominations between £ 5 and £ 1000.

During the early 20th century in America, gambling became outlawed and banned by state legislation and social reformers of the time.

During the 19th and 20th centuries, coin collecting increased further in popularity.

During the early 20th century, comic strips were widely associated with publisher William Randolph Hearst, whose papers had the largest circulation of strips in the United States.

During the early 20th century, a Caltech committee visited several universities and decided to transform the undergraduate housing system from regular fraternities to a house system.

During the 19th and 20th centuries, Chinese philosophy integrated concepts from Western philosophy.

During the early 20th century, two major publications successfully applied the principles developed by Gibbs to chemical processes, and thus established the foundation of the science of chemical thermodynamics.

During the 20th century, the church grew substantially and became an international organization.

During the middle of the 20th century the French reluctantly began to accede to reasonable requests, and in 1946 Comoros had become a separately administered colony from Madagascar.

During the 20th century, this trend continued with more modern and powerful revolver cartridges, in the form of Winchester and Marlin lever action carbines chambered in. 38 Special /. 357 Magnum and. 44 Special /. 44 Magnum.

During the late 19th and early 20th century mail was used as a material for bulletproof vests, most notably by the Wilkinson Sword Company.

During the 19th and early 20th centuries most monarchies maintained a mounted cavalry element in their royal or imperial guards.

During the late 19th and early 20th centuries, just the opposite was the case with little to no population concentration in major industrial centres as the predominantly rural resource-dependent Maritime economy continued on the same path as it had since European settlement on the region's shores.

During the 19th and 20th centuries, materialistic monism has became the norm.

During the first half of the 20th century, these opposing factions among the Christian Churches coexisted but with growing discomfort and tension.

During the 20th century Italian universities introduced more advanced research degrees, such as the Ph. D., and now that it is part of the E. U. Bologna Process, a new three-year first degree, or “ laurea ” ( equivalent to a B. A.

During the 19th and early 20th century, many smaller or less developed languages saw their first encyclopedias, using French, German, and English role models.

During the early 20th century, the rhymed epigram couplet form developed into a fixed verse image form, with an integral title as the third line.

During the early part of this century, the Brown & Sharpe works in Providence were unchallenged as the largest single manufacturing facility devoted exclusively to precision machinery and tool manufacture anywhere in the world.

During the nineteenth century these views were protested by virtually all the Latin American writers, though ineffectively, just as the new nations of Africa and Asia protest them, with more effect, today.

During the 17th century, practical alchemy started to evolve into modern chemistry, as it was renamed by Robert Boyle, the " father of modern chemistry ".< ref name =" Deem, Rich 2005 ">

During the Late Bronze Age circa 2000 BC, they created an empire, the Hittite New Kingdom, which reached its height in the 14th century BC, controlling much of Asia Minor.

During the 1st century BC the Armenians in what had been Urartu established the powerful Armenian kingdom under Tigran who reigned throughout much of eastern Anatolia between the Caspian, Black Sea and Mediterranean.

During the post-World War I period ski-lifts were built in Swiss and Austrian towns to accommodate winter visitors, but summer tourism continued to be important ; by the mid-20th century the popularity of downhill skiing increased greatly as it became more accessible and in the 1970s several new villages were built in France devoted almost exclusively to skiing, such a Les Menuires.

During the Carolingian epoch the custom grew up of granting these as regular heritable fiefs or benefices, and by the 10th century, before the great Cluniac reform, the system was firmly established.

During the fourth century, the Roman emperors commonly employed foederati: Germanic irregular troops under Roman command, but organized by tribal structures.

During the post-Phoenician era of the eighth century a palace was erected and a port was also constructed, which served the trade with the Greeks and the Levantines.

During the 4th century BC, there may well have been some 250, 000 – 300, 000 people in Attica.

During the 5th century BC, the Acropolis gained its final shape.

During the 3rd century, under threat from a Herulian invasion, repairs were made to the Acropolis walls, and the " Beulé Gate " was constructed to restrict entrance in front of the Propylaia, thus returning the Acropolis to use as a fortress.

During the 5th century, the Anglii invaded Great Britain, after which time their name does not recur on the continent except in the title of Suevi Angili.

During the late 19th century, ideas about the legendary nature of Atlantis were combined with stories of other lost continents such as Mu and Lemuria.

During the first half of the 19th century, some of the songs African-Americans sang also began to appear in use for shipboard tasks, i. e. as shanties.

During the quarter century 1826-1850, 41 species and 6 genera of Apicomplexa were named.

During the 19th century, the fields of science and art became increasingly intertwined as scientists such as Michael Faraday began to study the damaging effects of the environment to works of art.

During the next century Aegina was one of the three principal states trading at the emporium of Naucratis, and it was the only state of European Greece that had a share in this factory.

During the latter half of the 19th century, considerable public improvements were made to the town, which became, despite its neighbouring collieries, a pleasant place to live.