This happened in 1717.
Doubtless the Spaniards would at once have moved on against Sicily; but France and England now intervened more actively to prevent the general war that seemed threatening.

England sent a fleet to the Mediterranean, and negotiations began at Paris, Vienna, and Madrid.
The outcome of these conferences was an agreement between England and France to effect the exchange of Sardinia and Sicily just mentioned, recompensing Spain by giving her Parma and Tuscany in northern Italy, and stipulating that the emperor should renounce forever his absurd but irritating claim to the Spanish crown.

This arrangement was to be enforced by arms, if necessary.

The emperor at first refused consent; but the increasing greatness of Alberoni's preparations at last decided him to accept so advantageous an offer, and the accession of Holland to the compact gave it the historical title of the Quadruple Alliance.

Spain was obstinate; and it is significant of Alberoni's achievements in developing her power, and the eagerness, not to say anxiety, of George I., that the offer was made to purchase her consent by ceding Gibraltar.