In January 1718 the Conte Filippo d'Ussolo was sent to Vienna to negotiate an alliance with the emperor, but he exceeded his mandate by broaching the cession of Sicily, and was replaced at the end of April by Gian Giacomo Fontana. Now Victor Amadeus offered to cede Sicily in exchange for Sardinia and Vigevanasco, and Fontana, empowered to make an alternative suggestion, offered to exchange all Savoyard possessions on the mainland for Sardinia and Naples. By the time these offers received a hearing in June the emperor had adhered to the Triple Alliance, and the War of the Quadruple Alliance had begun. On 1 July the Spanish landed at Palermo. Greeted as liberators, they quickly expelled the Savoyard troops; only Milazzo put up any resistance, being reinforced by Austrian troops, until it fell on 15 October. On 2 August, Charles VI made peace with the Ottomans. On 7 August, Victor Amadeus sent the Marquis de Saint-Thomas to Vienna to offer Sicily in exchange for Parma and Tuscany, but he was rebuffed. On 11 August, the British fleet defeated the Spanish at the Battle of Cape Passaro, stranding the Spanish troops on Sicily. After numerous failed efforts to avert the inevitable in London and Paris, Victor Amadeus acceded to the Quadruple Alliance on 8 November 1718.