Events and ideas: 999-1200

* EVENTS

999 A scientist as well as churchman, Silvester II becomes pope.

1000 Norwegian Leif Eriksson lands in Vinland, perhaps Canada.

1050 Musical clefs and staves invented 1054 Schism between Greek Orthodox and Roman Catholic churches.

1065 Dedication of Westminster Abbey (right).

1066 Battle of Hastings.

1073 Hildebrand, defender of church liberty, becomes Pope Gregory VII.

1086 Domesday Book records first general census of England.

1170 Murder of St Thomas a Becket in Canterbury Cathedral.

1187 Saladin takes Jerusalem.

1198 Innocent III becomes pope, ensuring supremacy of Roman See.

* IDEAS

1037 Death of Avicenna, mediator of the scientific achievements of the ancient Greeks.

1066 Anselm's ontological proof of God's existence is developed.

1079 Birth of Abelard (below), influential theologian and philosopher.

1099 Jerusalem captured by Crusaders (below). End of first crusade.

1126 Birth of Averroes, interpreter of Aristotle to the Latin Middle Ages.

1150 Moors bring paper from China to Europe.

1158 Charter of the first university at Bologna.

1170 Leonardo Fibonacci born. Introduced Arabic numbers to Europe.

1175 University of Paris (below, left) established.

1188 University of Oxford established.

1190 Jew Maimonides's Guide to the Perplexed records biblical and Aristotelian teachings.