In 1503 a treaty was negotiated by Ferdinand's son-in-law, the Archduke Philip. Gonsalvo, however, not recognising instructions received from Philip, gave battle to the French at Cerignola, and won a brilliant victory. A few days earlier another victory had been won by a second column; and Gonsalvo marched on Naples, which welcomed him. The two French fortresses commanding it were reduced. Since Ferdinand refused to ratify Philip's treaty, a French force entered Roussillon; but retired on Ferdinand's approach. The practical effect of the invasion was a demonstration of the new unity of the Spanish kingdom. In Italy, Louis threw fresh energy into the war; and Gonsalvo found his own forces greatly out-numbered. In the late autumn there was a sharp but indecisive contest at the Garigliano Bridge. Gonsalvo held to his position, despite the destitution of his troops, until he received reinforcements. Then, on December 28, he suddenly and unexpectedly crossed the river; the French retired rapidly, gallantly covered by the rear-guard, hotly attacked by the Spanish advance guard. The retreat being checked at a bridge, the Spanish rear was enabled to come up, and the French were driven in route. Gaeta surrendered on January 4; no further resistance was offered. South Italy was in the hands of Gonsalvo. _IV.--After Isabella_ Throughout 1503 and 1504 Queen Isabella's strength was failing. In November 1504 she died, leaving the succession to the Castilian crown to her daughter Joanna, and naming Ferdinand regent. Magnanimity, unselfishness, openness, piety had been her most marked moral traits; justice, loyalty, practical good sense her political characteristics--a most rare and virtuous lady. Her death gives a new complexion to our history. Joanna was proclaimed Queen of Castile; Ferdinand was governor of that kingdom in her name, but his regency was not accepted without demur. To secure his brief authority he made alliance with Louis, including a marriage contract with Louis' niece, Germaine de Ford. Six weeks after the wedding, the Archduke Philip landed in Spain. Ferdinand's action had ruined his popularity, and he saw security only in a compact assuring Philip the complete sovereignty--Joanna being insane. Philip's rule was very unpopular and very brief. A sudden illness, in which for once poison was not suspected of playing a part, carried him off. Ferdinand, absent at the time in Italy, was restored to the regency of Castile, which he held undisputed--except for futile claims of the Emperor Maximilian--for the rest of his life.