On the other hand, the old jealousy of Venice was by no means dead, and the Ragusans were suspicious of her every movement, fearing that by a _coup de main_ she might capture the city, and thus unite her Dalmatian possessions with Cattaro and gain an unbroken line of posts all down the Adriatic. That Ragusa’s fears of Venetian hostility were not groundless became manifest the following year. Venice was then at war with Alfonso of Ferrara; the causes of that war offer a curious parallel with those of Venetian hostility towards Ragusa. Like Ragusa, Ferrara was an independent State placed between the main Venetian possessions and an outpost—in this case Ravenna. In addition there were disagreements on account of the salt monopoly and the navigation dues, as in the case of Ragusa. A Venetian flotilla was blockading the entrance to the Po and besieging the city. Some Ragusan galleys happened to be up the river, and were detained by Ippolito d’Este, who utilised them and their crews for the defence. When the Venetian fleet under Angelo Trevisan attempted to sail in it was repulsed by the shore batteries, with the help, it is said, of the Ragusan gunners. The Venetian Government out of revenge issued a decree which greatly hampered Ragusan trade with Venice and her possessions (September 21, 1484). Ragusan residents and merchants were expelled from Venice, and all Ragusan ships forced to pay 100 ducats as anchorage dues, while some of them were seized as compensation for the damage suffered at Ferrara.[426] Other impositions were also levied, and although the dispute was settled soon after, mutual distrust continued as before. In 1490 Matthew Corvinus died, and the disappearance of that able and warlike monarch caused a recrudescence of Turkish activity in all directions. In 1492 the Republic suffered from the raids of Kosača’s renegade son Achmet. Kosača had left large sums of money at Ragusa in trust for his sons, and Achmet, who had already received his share, now demanded that it should be paid over again, and accused the Republic before the Sultan of having robbed him. Although the Ragusan ambassadors showed Bayazet Achmet’s receipt, the Sultan ordered the Republic to pay 100,000 ducats at once. The new King of Hungary, Ladislas II., promised help, but as it was not forthcoming the Republic had to pay.