Immediately upon hearing the news of Kossova, the Venetian Senate sent to Andrea Bembo, who had been negotiating with Murad, a letter instructing him as to the course he should follow in view of the death of Murad. He was to seek out the son who had survived, or, if both sons were alive, to be very cautious until one son had killed or defeated the other. In the meantime, he was to make overtures to both, telling each one, without letting the other know, that the Senate ‘had heard of the death of his father, and on that account had great sorrow. For we have always regarded him as a most particular friend, and we loved him and his state. Likewise we have heard of his happy elevation to the power and lordship of his country, concerning which we have been very happy, because, in like manner as we have sincerely loved the father, we love and are disposed to love the son and his dominion, and to regard him as a particular friend.’ Then Bembo was to speak of the commercial privileges desired by the Senate, and to disclaim the action of the Venetian admiral, Pietro Zeno, who had attacked the galleys of Murad.[492] Immediately upon hearing which son had become the successor of Murad, the Senate sent Francesco Quirini to Bayezid with gifts to secure the renewal of the commercial treaty concluded several years before with Murad. Bayezid readily offered to protect Venetian commerce, but he gave no guarantee.[493] The appearance of the Osmanlis on the Aegaean Sea, and their sacking of Chios, Negropont,[494] and Attica, greatly alarmed the Senate. Fear was expressed for the safety of the Venetian fortresses in Negropont and Crete.[495] All garrisons were ordered, provisioned, and reinforced.[496] In 1393, forgetting their sincere love for Bayezid, the Senate decided to treat with Sigismund for an offensive alliance against the Osmanlis.[497] So it cannot be believed that the Venetians did not see the growing danger.