Q
Quadrilateral.
The name given to four fortresses in Northern Italy, Peschiera, Mantua, Legnago and Verona.
Quadrilateral, Bulgarian.
The four fortresses of Varna, Silistria, Rustchuk and Schumla are known by this name.
Quadrilateral Treaty.
A treaty signed in 1840, by Great Britain, Austria, Prussia, and Russia, by which the signatories bound themselves to protect the Porte against aggression.
Quadruple Alliance, 1718.
An alliance between England, France, Austria and Holland, formed to prevent Spain recovering her former possessions in Italy. It became the Quadruple Alliance through the adhesion of Austria to the Triple Alliance of 1717. Its operations were completely successful, and Spain gave way in 1719.