1270-1289 Marco Polo, Specs & Mongols Invade Japan

This twenty year period covers the reign of Henry III of England at a time when Marco Polo (pictured) was journeying to China

The longest period of relative world peace and safety  was about 6 years -- after the 8th Crusade in 1270, the 1274-1281 Mongol invasion of Japan and the 1284 War of The Sicilian Vespers.

In 1271 a new pope -- Gregory X -- was elected after three years of delays which finally caused the new king of France, Philip III, and Charles of Anjou to intervene and force the issue.

At the time of his election, Gregory X was in the Holy Land on crusade with Prince Edward of England who, with Henry III's death in 1272, became Edward I.

On his return to Rome, Gregory and the eastern emperor Michael Palaeologus met in 1274 to heal the rift between the eastern and western church.

Gregory X also reformed the election of popes, and approved the election of a new German king in 1273 -- Rudolf I, Holy Roman Emperor, who founded the Hapsburg dynasty -- on proviso that he relinquished German claims to the papal states and Sicily.

In 1275 Marco Polo journeyed to China and in 1286 convex spectacles were invented by Italians.