Title: 685
Content: September &ndash; Emperor Constantine IV dies of dysentery at Constantinople after a 17-year reign, and is succeeded by his 16-year-old son Justinian II. 
Title: Constantine the Great
Content:  as he did so as to be absolved from as much of his sin as possible. Constantine died soon after at a suburban villa called Achyron, on the last day of the fifty-day festival of Pentecost directly following Pascha (or Easter), on 22 May 337. Although Constantine's death follows the conclusion of the Persian campaign in Eusebius's account, most other sources report his death as occurring in its middle. Emperor Julian the Apostate (a nephew of Constantine), writing in the mid-350s, observes that the Sassanians escaped punishment for their ill-deeds, because Constantine died "in the middle of his preparations for war". Similar accounts are given in the 
Title: Constantine the Great
Content:   From his recent illness, Constantine knew death would soon come. Within the Church of the Holy Apostles, Constantine had secretly prepared a final resting-place for himself. It came sooner than he had expected. Soon after the Feast of Easter 337, Constantine fell seriously ill. He left Constantinople for the hot baths near his mother's city of Helenopolis (Altinova), on the southern shores of the Gulf of Nicomedia (present-day Gulf of İzmit). There, in a church his mother built in honor of Lucian the Apostle, he prayed, and there he realized that he was dying. Seeking purification, he became a catechumen, and attempted a return to Constantinople, making it 
Title: Constantine Arianiti
Content:  as governor, Constantine lived in the nearby mountain village of Montefiore Conca, also granted to him by Clement, rather than in Fano itself, given that the castle in Montefiore Conca was nearly impenetrable. Constantine died in Montefiore Conca on 8 May 1530 and was buried in Santi Apostoli or Sant'Agostino in Rome. Two of Constantine's claimed titles, 'Prince of Macedonia' and 'Duke of Achaea', were inscribed on his tomb. The precise location of his grave is not known. Constantine's son Arianitto continued his father's aspirations and pretensions, though the only of his father's titles he is attested to have used was 'Prince of Macedonia'.
Title: 337
Content: May 22 &ndash; Constantine the Great, first Christian Roman emperor of the Western Empire (312–324), and of the Roman Empire (324–337), dies in Achyron, near Nicomedia, at age 65, after he is baptized by Eusebius of Nicomedia. ; September &ndash; A number of descendants of Constantius Chlorus, and officials of the Roman Empire, are executed for a purge against the sons of Constantine I. ; September 9 &ndash; Constantine II, Constantius II, and Constans succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three Augusti (see map). 
Title: Constantine of Irinoupolis
Content:  Constantine of Irinoupolis died from congestive heart failure on May 21, 2012 in Pittsburgh, Pennsylvania at the age of 75.
Title: Constantina
Content:  name and fate are unknown. Constantina and Constantius Gallus were then sent from Rome to Syria at Antioch to govern that portion of the Eastern Roman Empire. She would not return to Rome until her death. In AD 354, when Constantius called for Gallus, the caesar sent Constantina to her brother, with the purpose to mitigate his position in Constantius' consideration. While on her way to meet with Constantius II, she died at Caeni Gallicani in Bithynia (Asia Minor). The cause of her death was a sudden high fever of unknown cause. Her body was sent back to Rome and entombed near Via Nomentana in a mausoleum her father, Emperor Constantine I, had started building for her. This mausoleum would later become known as the church of Santa Costanza, when Constantina was venerated as saint. Her porphyry sarcophagus is on exhibit in the Vatican Museums.
Title: Mediana
Content:  Constantine the Great (280–337) was born and raised in Naissus. He erected a majestic residence in one of the luxurious suburbs of ancient Naissus, where he often resided and attended to state affairs. Historical records testify it was in Naissus that he passed several laws – in 315, 319, 324, and 334. After Constantine's death in 337, the imperial residence in Mediana was used by several other emperors, either as a place of rest on their long journeys or during preparations for war. Thus, Constantine's sons, Constantius II and Constans, stayed in Naissus in the winter of 340, for they signed an edict there. Later on, Constans used it as a temporary residence. According to the Hieronimus' Chronicles, after Vetranio, commander of the Danubian army, had been proclaimed emperor in Sirmium, he surrendered the insignia of 
Title: Constantine I of Greece
Content:  He spent the last four months of his life in exile in Italy and died at 1:30 AM on January 11, 1923 at Palermo, Sicily of heart failure. His queen, Sophie of Prussia, was never allowed back to Greece and was later interred beside her husband in the Russian Church in Florence. After his restoration on the Greek throne, George II organized the repatriation of the remains of members of his family who died in exile. An important religious ceremony that brought together, for six days in November 1936, all members of the royal family still alive. Constantine's body was buried at the royal burial ground at Tatoi Palace, where he still rests today.
Title: Constantine XI Palaiologos
Content:  Constantine died the day Constantinople fell. There were no known surviving eyewitnesses to the death of the emperor and none of his entourage survived to offer any credible account of his death. The Greek historian Michael Critobulus, who later worked in the service of Mehmed, wrote that Constantine died fighting the Ottomans. Later Greek historians accepted Critobulus's account, never doubting that Constantine died as a hero and martyr, an idea never seriously questioned in the Greek-speaking world. Though none of the authors were eyewitnesses, a vast majority of those who wrote of Constantinople's fall, both Christians and Muslims, agree that Constantine died 

Question: where did emperor constantine die?
Answer: Constantinople.