1240. Emperor Frederick II advances against Pope Gregory IX and threatens Rome. The Pope declares a crusade against him.
Batu Khan, at the head of Mongols of the Golden Horde, overruns and devastates Russia.
On the Neva, Alexander, Prince of Novgorod, gains a great victory over the Swedes.
1241. Hamburg and Lubeck form an alliance to protect their commerce. See "RISE OF THE HANSEATIC LEAGUE," vi, 214.
Central Europe is invaded by the Mongols, or Tartars, who vanquish the Silesians, Poles, and Teutonic Knights at Wahlstatt; they defeat the Hungarians on the Sajo.
A Pisan and Sicilian fleet, by order of Frederick II, captures twenty-two Genoese galleys in which cardinals, prelates, and ambassadors, summoned by the Pope, were proceeding to hold a council at Rome; the prisoners were held at Naples and Apulia.
1242. Aldermen first elected in London.
Asia Minor is invaded by the Mongols.
Alexander Nevski, son of Jaroslav, defeats the Swedes and Knights
Swordbearers at Lake Peipus.
1243. Frederick II urges the cardinals to appoint a pope; he releases some of his prisoners to attend the conclave.