OK, this is a potential TL for my steampunk/magitek idea:
1845: certain ancient monuments, such as Stonehenge, the Pyramids of Giza, the Taj Mahal or Chichen Itzá start to shine without any reason. People living nearby them start to show strange abilities, such as control over fire or water.
1850: all around the world, dragons start to wake up, after having slept for thousands of years. A few of them are feral, some more are quite intelligent and wish to control humanity, but most are willing to help humans. They explain to humanity that what is happening is magic. There are many riots of religious origin against magically able people, but things are quite shaken up when the Catholic Pope publishes an enciclical in which he asks all Christians not to act violently against magically able people, but to convert them to Christianity so that they may use those powers for good. There are rumours that the Pope himself is able to practice magic, but none of those rumours are confirmed.
1855: Slowly, the use of magic has permeated through the population as it becomes more useful for everyone's everyday's lives. The United Kingdom, having direct access to several of the most powerful magical sites (Stonehenge in the Isles, Taj Mahal in India, the Pyramids in Egypt, Uluru in Australia) becomes even more powerful thanks to these places, and the Industrial Revolution that had started the previous century becomes a Magitek Revolution, with magic becoming a part of industrial processes. While this destroys many jobs, it also creates many more jobs as new markets of all kinds are opened to the people.
1860: the election of Abraham Lincoln to the office of President of the United States sparks the secession of South Carolina from the Union.
1861: the attack on Fort Sumter starts the American Civil War.
1862: with a stalemate on the field, Abraham Lincoln pushes into law the Emancipation Proclamation, by which all slaves within the Union and the Confederacy are to be freed. Several riots happen in the borders states that still have slaves, but threats of further secession are brought down thanks to the Magic branch of the Army.
1863: Lincoln, using magical means, approaches the main remaining Native American tribes in the Union. He promises to allow all of them to live in several territories (Arizona or Oklahoma) where they will be able to live free of white man settlement, provided that they eventually become states of the Union, if they help the Union in the war against the South with their shamanic powers. After a discussion, they agree.
1864: thanks to the alliance with the Native American tribes, as well as their better armed armies, the Union brings the Confederacy down. Slaves are freed and allowed to move towards the west to settle there.
1865: after being chosen to be the President of the USA for a second time, after riding on the success of winning the American Civil War, Lincoln keeps his promise and establishes the Territories of Oklahoma and Arizona as Native American. Heavy protests are brought down when Lincoln reminds them that there is still a lot of space in America for them.
1869: the Spanish Parliament votes for Leopold of Hohenzollern to become the new King of Spain. This sparks an angry answer from Napoleon III's France, who finds itself surrounded by its German enemy.
1870: the Franco-Prussian War ends by the end of this year, with Germany defeating France easily thanks to their better discipline and weaponry. France loses Alsace and Lorraine and has to pay reparations.
1878: Spain manages to pacify Cuba, Puerto Rico and Philippines thanks to the progressive movements of the new king, who favours the extension of a system similar to that of the Vascongadas to all the nation.
1871-1900: Africa is divided by the European nations, as they look for more magical sites that will make them more powerful in the international scene. They also look to Asia as potential sources of bigger markets and magical sites are opened.
1898: the Qing Emperor, Guangxu, manages to win in the battle against Empress Dowager Cixi and orders her killed for rebellion. He also successfully extends the initial Hundred Days Reform into a much longer period that restorates Chinese national unity and brings modernization to China.
1912: the Titanic avoids sinking thanks to a Fire Mage who melts an iceberg the ship was about to hit.
1914: the Great War starts after Serbia denies Austrian agents and mages unlimited access to Serbia in order to search for the assassins of Archduke Franz Ferdinand. Germany, Spain and Italy back Austria, while France and Russia back Serbia. The British Empire joins the war after Germany invades Belgium. Spain invades Gibraltar successfully.
1916: The United States joins the war after it is discovered Germany asked Mexico to join the war in their side, in exchange of the land they lost to the US in the Mexican-American War.
1917: As Germany starts to be pushed out of Belgium, their mages start to resort to desperate measures. Three mages sacrifice themselves to produce a spell that will sink Washington D.C slowly over a period of several weeks, their hope being that it will force America to keep their army back home. Many die in this first attack against civil population. The United States avenges this loss with a meteoric bombardment of Munich and sending several hundreds of thousands of soldiers to France. The Russian White Revolution brings the autocratic czarist regime down, but the Red Revolution doesn't work out as well because most mages are loyal to the Kerensky government, and the Russian Civil War starts in earnest, bringing Russia out of the war.
1918: A very radicalized Kaiser Wilhelm II orders his best mages to destroy London and Paris. London is sunk in a few days under the waters of the North Sea, creating the Thames Bay, while a mountain grows under Paris and destroys the whole city. An Anglo-French mage force utterly destroys Berlin, Hamburg and Hanover by bringing up volcanos that swallow those cities. The entrance of Entente armies into Germany proper doesn't mean it's the end of the war, though.
1919: The effects of the destruction of so many important cities start to make their hole in the world. Riots hit several nations when critical supplies start to fall short, despite mages' attempts to grow high quantities of food and other necessary things with their powers. Nearly all of Africa falls into chaos as natives make the most of the colonial powers distraction to bring civilization down there with their magical abilities.
1920: The Russian Civil War ends, but not because of one side winning, but because both sides have fallen. The last few Soviet mages attempt to destroy Petrograd as a parting shot, but for some reason they have an epic fail and instead destroy Tokyo, bringing down the Japanese Empire.
1921: The dragons, who had been telling people that, if they didn't heed their words, they would leave, make their threats reality by not only leaving, but also killing all mages and making most magic-reliant objects explode. The few nations that still survived fall when their over-reliance on magic makes everything useless.
1945: All nations in the world have fallen due to everything that has happened in the last century. Nearly a half of humanity has died off in the Great Magical War and the Magical Catastrophes. The rest survive on farms and communities that manage to keep going on thanks to whatever technology was salvaged from the cities and the few people with magical powers that have been born after the dragons departing.
1950: Magical sites start to shine again... but few people realise this.