Christianity in the 13th century

In addition, the century can be seen as period in which the study of Natural Philosophy that could anachronistically be called 'science' began once again to flourish in the hands of such men as Robert Grosseteste and Roger Bacon.

Notable authors include: The monastic orders, especially the Benedictines, Cistercians, and Premonstratensians, continued to have an important role in the Catholic Church throughout the 13th century.

The four Mendicant Orders recognized by the Second Council of Lyon are: The Fourth Crusade, authorized by Innocent III in 1202, intended to retake the Holy Land but was soon subverted by Venetians who used the forces to sack the Christian city of Zara.

Many things that were stolen during this time: holy relics, riches, and many other items, are still held in various Western European cities, particularly Venice.

Because they subsequently lacked provisions and time on their vessel lease, the leaders decided to go to Constantinople, where they attempted to place a Byzantine exile on the throne.

After the Sack of Constantinople, much of Asia Minor was brought under Roman Catholic rule, and the Latin Empire of the East was established.

This is in light of perceived Roman Catholic atrocities not exclusive to the capital city of Constantinople in 1204 starting the period in the East referred to as Frangokratia.

The Teutonic Order's attempts to conquer Orthodox Russia (particularly the Republics of Pskov and Novgorod), an enterprise endorsed by Pope Gregory IX,[3] can also be considered as a part of the Northern Crusades.

Many in the East saw the actions of the West in the Mediterranean as a prime determining factor in the weakening of Byzantium which led to the empire's eventual conquest and fall to Islam.

[5] Abuses committed during the crusade caused Innocent III to informally institute the first papal inquisition to prevent future aberrational practices and to root out the remaining Cathars.

[7][8] Over time, other inquisitions were launched by the Church or secular rulers to prosecute heretics, to respond to the threat of Moorish invasion or for political purposes.

The story is that an outburst of the old popular enthusiasm led a gathering of children in France and Germany, which Pope Innocent III interpreted as a reproof from heaven to their unworthy elders.

None of the children actually reached the Holy Land; those who did not return home or settle along the route to Jerusalem either died from shipwreck or hunger, or were sold into slavery in Egypt or North Africa.

By processions, prayers, and preaching, the Church attempted to set another crusade afoot, and the Fourth Council of the Lateran (1215) formulated a plan for the recovery of the Holy Land.

In the second phase, crusader forces achieved a remarkable feat in the capture of Damietta in Egypt in 1219, but under the urgent insistence of the papal legate, Pelagius, they launched a foolhardy attack on Cairo in July 1221.

Emperor Frederick II had repeatedly vowed a crusade but failed to live up to his words, for which he was excommunicated by Pope Gregory IX in 1228.

He nonetheless set sail from Brindisi, landed in Palestine, and through diplomacy he achieved unexpected success: Jerusalem, Nazareth, and Bethlehem were delivered to the crusaders for a period of ten years.

In 1229 after failing to conquer Egypt, Frederick II of the Holy Roman Empire made a peace treaty with Al-Kamil.

Although the Mongols successfully attacked as far south as Damascus on these campaigns, the ability to effectively coordinate with Crusades from the west was repeatedly frustrated most notably at the Battle of Ain Jalut in 1260.

[14][15] The Teutonic Order's attempts to conquer Orthodox Russia (particularly the Republics of Pskov and Novgorod), an enterprise endorsed by Pope Gregory IX, can be considered as a part of the Northern Crusades.

The Second Council of Lyon was convoked to act on a pledge by Byzantine emperor Michael VIII to reunite the Eastern church with the West.

[17] On 15 August 1219, during the feast of the Dormition of the Mother of God, archimandrite Sava was consecrated by Patriarch Manuel I of Constantinople in Nicaea as the first Archbishop of the autocephalous (independent) Serbian Church.