The King of Sicily having now consented to the terms of the Quadruple Alliance, Byng received on board two thousand Austrian troops to be landed at Messina.

When he appeared before the place, finding it besieged, he wrote to the Spanish general suggesting a suspension of arms for two months.

This was of course refused; so the Austrians were landed again at Reggio, in Italy, and Byng passed through the Straits of Messina to seek the Spanish fleet, which had gone to the southward.
The engagement which ensued can scarcely be called a battle, and, as is apt to happen in such affairs, when the parties are on the verge of war but war has not actually been declared, there is some doubt as to how far the attack was morally justifiable on the part of the English.
It seems pretty sure that Byng was determined beforehand to seize or destroy the Spanish fleet, and that as a military man he was justified by his orders.

The Spanish naval officers had not made up their minds to any line of conduct; they were much inferior in numbers, and, as must always be the case, Alberoni's hastily revived navy had not within the same period reached nearly the efficiency of his army.

The English approached threateningly near, one or more Spanish ships opened fire, whereupon the English, being to windward, stood down and made an end of them; a few only escaped into Valetta harbor.