1250-1269 Baghdad Falls, Germans Unpopular in Rome

This twenty year period covers the reign of Henry III of England and the Mongol capture of Baghdad in 1258.

In this period the longest period of relative world peace and safety was in the first eight years to the Capture of Baghdad, then came the 1262-1267 Berke-Hulagu war, the 1264-1267 Second Barons' War and the 1265-1266 Aragonese-French War.

In Rome, Innocent IV was pope and the Holy Roman Emperor was Frederick.

 Frederick died in 1250 and was succeeded by his son Conrad. There was conflict between the emperor and Pope Innocent IV continued until both died in 1254.

Innocent was succeeded by Pope Alexander IV and Conrad by his young son Conradin who was a ward of the papacy.

Alexander took advantage of the situation to try to rid Italy of German kings.

The kingdom of Sicily was offered to the English Prince Edmund, Henry III's son, but Henry could not afford the military cost involved. On hearing this, Manfred, Conradin's bastard brother was stirred in 1258 to take Sicily and pronounce himself as King of Sicily.

Pope Alexander died in 1261 and was replaced by Urban IV who offered Sicily to Louis IX's younger brother, Charles of Anjou, on condition of payment of a lump sum of money and annual tribute.

Manfred retaliated, attacked the papal states and the Pope fled to Perugia where he died in 1264, replaced by Clement IV who, like Urban, was a Frenchman and urged Charles of Anjou to hurry to Italy with a French army.

Manfred was defeated in 1266 and by then his brother, Conradin, had come of age. When Conradin claimed his heritage he was beheaded by Charles of Anjou, leaving Pope Clement IV to realize he had merely exchanged German domination with French domination.

In 1267 the eastern emperor Michael Palaeologus renewed his earlier suggestion to reunite the eastern and western churches -- this time with the Roman Pope in supremacy-- but Clement, with Charles of Anjou's encouragement, wanted to conquer Constantinople by force and make it a Roman city.

Coincidentally, in 1250 arsenic was discovered by Albertus Magnus and became a favorite form of poisoning from then on.

1230-1249 Mongols Invade Eastern Europe

This twenty year period covers the reign of King Henry III of England and the Mongol invasions of Europe.

The Holy Roman Emperor was Frederick II and Gregory IX was pope. In the year that the excommunicated Frederick returned from the 6th Crusade in the Holy Land, 1237, he was faced with the Mongol conquest of Eastern Europe.

The Mongols had been invading Eastern Europe since 1223, and by 1236 had taken the Volga in Bulgaria.

In 1240 there was a war between Russia and Sweden, followed by more Mongol invasions of Europe in 1241-1242.

In 1242 there was a Teutonic-Novogorod War and in 1248 -- as if they didn't have enough trouble on their hands -- the Pope authorized the 7th Crusade to the Holy Land.

The conflict between Frederick II and Gregory IX continued, this time over Sicily and Lombardy with Frederick wanting to rule over the whole of Italy. His army surrounded Rome, and then Gregory died in 1241, replaced by the elderly Celestine IV who died after 17 days as pope, to be replaced by Innocent IV in 1243.

The selection of a new pope was made difficult by Frederick taking some cardinals prisoner. Pope Innocent fled to Lyons, convened a general church council in 1245 to depose Frederick who, naturally, challenged the pope's authority.

Louis IX of France vacillated between allegiance to Frederick -- the Holy Roman Emperor -- and Innocent -- the Roman Pope -- trying to mediate, but the advent of the 7th crusade to the Holy Land diverted everyone's attention.

1210-1229 Magna Carta, Mongol Invasions, More Crusades

This twenty year period covers the reign of King John of England who died in 1216 -- after signing the Magna Carta in 1215 -- and was succeeded by his son Henry III.

In this period there was constant warfare in the world, one war finished somewhere, another one started somewhere else, but mostly they just overlapped each other.

First was the 1211-1276 Mongol invasion of China; then came the 1213 -1214 Angevin-Flanders War; the 1215 -1217 First Barons' War; and the 1218 -1222 Mongol invasion of Central Asia.

The Fifth Crusade to the Holy Land was in 1218; then came the 1223 -1480 Mongol invasion of Russia; the 1223 -1236 Mongol invasion of Volga Bulgaria; and the Sixth Crusade to the Holy Land in 1228.