What were the Crusades?

Holy wars, or expeditions, undertaken by the Christians against the Turks and Saracens, to recover Palestine, between the years 1100 and 1400.

What causes led to these wars?

Many circumstances contributed to give rise to them. They were undertaken, first, with a view to protecting the devout Christian pilgrims, who were in the habit of frequenting the venerable places where our Saviour had lived, taught, suffered, and triumphed, from the fury and avarice of the heathens; secondly, with a view to getting possession of the Holy Land itself, and of annexing it to Christendom; and thirdly, to break down the power of Mohammedanism, and to elevate the Cross in triumph and victory over Palestine.

Avarice, an excessive desire of gain.

Annexing, adding, joining.

What badge or sign was worn by those who engaged in the Crusades?

They distinguished themselves by crosses of different colors, worn on their clothes; from which they took the name of Croisés, or Cross-bearers; each nation wore different colors: for instance, the English had white crosses, the French red, and so on.

To what invention is the art of Navigation much indebted?