1470-1489 Spanish Inquisition

With the Spanish Inquisition and the murder of Edward IV's sons, this twenty year period covers murderous times. 

When Edward IV died in 1483 he was succeeded by his 12-year old son Edward V who was never crowned and reigned for only 78 days being imprisoned with his younger brother Richard in the Tower by their evil uncle Richard, Duke of Gloucester, and then executed -- the crown being taken by their uncle and murderer, Richard III.

Richard III died in 1485 and because his son Edward had died the year before, Henry VII came to power by virtue of being the husband of Elizabeth of York -- Edward V's sister -- but he steadfastly claimed the throne in his own right through a vague genealogy back to John of Gaunt, Edward III's son.

In this period there were only two wars -- the 1474-1477 Burgundian Wars between the Duchy of Burgundy and the Swiss Confederation, and the 1478 War between the Principality of Moscow and the Republic of Novgorod -- but from 1478 the Spanish inquisition of 1478

In 1471 the Portuguese reached the Gulf of Guinea in Africa and established a trade similar to the Arabs' on the east coast of Africa. 

In 1478 the Spanish inquisition commenced and in 1486 Maximilian established the German Hapsburg empire.

In 1483 the estimated population of Japan was 15m, Europe 73m, India 110m, China 120m, N and S America 11m, the Near East 23m and Africa 39m.

1450-1469 Gutenberg Invents Printing Press, Constantinople Falls

This twenty year period covers the reign of Henry VI whose kingship was usurped in 1461 by the Plantagenet Edward IV. In this period there was constant warfare in the world, but this period was glorious for the 1454 invention of the printing press by Gutenberg and the 1450 Italian invention of spectacles for short sightedness.

The 1425-1454 Wars in Lombardy were ongoing, and then came the 1453 Fall of Constantinople, the 1454-1466 Thirteen Years' War and the 1455-1485 Wars of the Roses.

The Turkish capture of Constantinople in 1453 was significant because it brought to an end the Byzantium Empire which, in 641, was all that remained of the former eastern Roman Empire. It was just a small area around Constantinople, exclusively Greek, which had reverted to its former Greek name - Byzantium. From 641 to 1453 the Byzantium emperors had ruled continuously.

In 1450 spectacles for short sightedness were invented in Italy and in 1454 Gutenberg invented the printing press (which later allowed humanism to spread throughout northern Europe).