[Sam the Sham]

Excellent analogy.

The Byzantines outsourced their sea going trade to the Venetians. Result ? The Fourth Crusade and the sack of Constantinople by these same Venetians.

[A. Pole]

The Byzantines outsourced their sea going trade to the Venetians. Result ? The Fourth Crusade and the sack of Constantinople by these same Venetians

Also the oligarchy managed to avoid paying taxes. Tax burden was on the working people/farmers. When Turks were taking Constantinople average people were not willing to fight. Only few thousand paid troops were available for the defence.

[Question_Assumptions]

The Byzantines even forgot how to sail. My Byzantine history professor told us of a Byzantine attempt to build a warship but they were so inept that they abandoned ship when it was caught up in the Bosphorus currents. The Italians boarded it and sailed it back and forth in front of the city, dragging their flag in the water.

But I was thinking of the Turks. Various Byzantine nobles kept importing Turkish mercenaries to fight their wars with each other and to work their land. By the time the Turks rolled up to Constantinople with their cannons, the countryside was already filled with Turks. Ultimately, there weren't enough Byzantines left to fight the Turks or hold on to their territory so they vanished to the conquerers, despite their wealth and long history of achievements.