1100s: Here's a recent Slate article on the 12th-century Lewis Chessmen. (The shield-chewing berserker rook is probably my favorite, with the pensive queen a close second.)
1200s: A blog entry, lavishly illustrated, on the geological and strategic importance of the town of Stirling during the wars of William Wallace. Look closely enough and you can see a tiny figure of Mel Gibson, mooning his adversaries.
1300s: The 14th-century Arab traveler, Ibn Battuta, who journeyed 75,000 miles during his lifetime, is being honored with a videogame. Apparently, there are zap guns.
1400s: While we're on the subject of guns, want to watch a short video demonstrating the use of the Hussites' early 15th-century handguns, the pistala (pipe gun) and hakovnice (hook gun)? Of course you do. (The clip is about halfway down the page).
1500s: Double-entry bookkeeping was first used in Europe in the 14th century, but the first popular text on the practice, Quaderno doppio col suo giornale, wasn't published until 1540. A webpage from the AMS follows the narrative of this 16th-()century textbook and finds that it is still a useful explanation of this accounting practice.
1600s: Sarah Underwood and Kathleen Brown try to guess what the 17th-century Pilgrims must have smelled like at the first Thanksgiving. Best not to read this one before dinner.*
1700s: Lynn Hunt, one of the world's experts on the 1789 French Revolution, recommends the five most influential books on the subject. Looks like I'm going to have to read R.R. Palmer's opus fairly soon.
1800s: The U.S. Mint will issue two coins in March 2012 honoring the bicentennial of the War of 1812. The coins will refer to the two images that most Americans associate with the war: the Star-Spangled Banner, and unnamed warships firing desultory broadsides at each other.
1900s: Did the French build a fake Paris during the First World War to fool German aerial bombers? Apparently so.
2000s: And Hungary has apparently decided that the best way to start the second decade of the 21st century is to slide back into fascism...
(Update, 12 July 2018: The Underwood and Brown piece is no longer available, but this more recent essay by Ruth Goodman suggests the Pilgrims didn't smell as bad as one might think.)