Pavle Strugar, 71, was found guilty of violating laws and customs of war, for not doing enough to deter the attack on civilians and for not punishing the officers responsible. He was acquitted of murder and of having ordered the bombing of the medieval port during the 1991-95 war between Yugoslavia and Croatia.
More than 50 people were killed, hundreds wounded and dozens of ancient buildings within the Old Town - a Unesco world heritage site - were destroyed during the three month siege of the city which began soon after Croatia declared independence from Yugoslavia in July 1991.
Strugar had pleaded not guilty to six counts of war crimes, including murder, cruel treatment of civilians and destroying cultural landmarks in a 10-hour bombardment from land and sea on 6 December 1991.
Judge Kevin Parker, at the International Criminal Tribunal for former Yugoslavia in the Hague, noted that a lower-ranking naval admiral, Miodrag Jokic, ordered the 6 December attack on Dubrovnik. Jokic, 70, was last March sentenced to seven years in prison.
But Strugar, as Jokic's superior, "should have seen the urgent need to determine if the Yugoslav People's Army artillery was in fact shelling the town without justification, and if so, assure the attack on the Old Town was stopped," the judge said. "He did not do so."
"You were not the immediate commander of those responsible. That was Admiral Jokic. Your criminal liability arises because you failed to take adequate measures to stop the shelling of the old town and because you failed to ensure that those responsible for the attack were disciplined."
Judge Parker said the court took into account Strugar's deteriorating health, age and other personal matters in deciding his sentence. His lawyers said they would appeal. Strugar will remain in custody before being transferred to another country to serve his sentence, pending the outcome of the appeal.
wThe European Union yesterday threatened to postpone membership talks with Croatia, due to begin next month, saying the former Yugoslav republic was not doing enough to hand over a fugitive war crimes suspect to the court in the Hague.
EU leaders are starting entry negotiations with the Balkan nation on 17 March if its government cooperates fully with the UN war crimes investigators by helping to bring ex-General Ante Gotovina before the tribunal. The EU's executive Commission said Zagreb seemed to lack the will to catch Gotovina, who they believe is hiding in Croatia or the Croat area of Bosnia - within the reach of the government.
Enlargement Commissioner Olli Rehn said: "If there is no progress on the Croatian side we are prepared to postpone talks."