The Diocese of Lacedaemon o Lacedaemonia () was a Christian ecclesiastical province in Laconia, Greece. Extant from at least the middle of the 5th century, it became a metropolis in 1083. During the period of Frankish rule, between ca. 1209 and 1278, it was held by Roman Catholic prelates, and remains a (vacant) titular see of the Catholic Church. The Greek Orthodox see was restored with the Byzantine reconquest in the 1270s, and continued until the see's abolition in 1852.
History
Establishment and first Byzantine period
Christianity came to Laconia and its capital, Sparta, in the 1st century AD, with the first church mentioned in Sparta in ca. 150 AD. Like the rest of the Peloponnese, the Christian community of Sparta was under the jurisdiction of the See of Corinth. A certain Hosios is the first bishop of Sparta attested, in 458; the see was called Lacedaemon , which was the common name for both Sparta and its surrounding region in Byzantine times.
The Chronicle of Monemvasia claims that the inhabitants of Sparta left their city for Sicily due to the Slavic invasions of the late 6th century, and that it was not until the early years of the 9th century that Emperor Nikephoros I (reigned 802–811) rebuilt the city and resettled it with Greek and Armenians settlers. Nevertheless, in the Sixth Ecumenical Council of 681, a Theodosios, "bishop of the city of the Lacedaemonians", participated, and a bishopric of "Lakedeon" is attested in a Notitia Episcopatuum of ca. 800.
With the raising of the Bishopric of Patras to a metropolitan see in 806, Lacedaemon (along with the bishoprics of Methoni and Koroni) passed from Corinth to Patras; Lacedaemon assuming the first rank (protothronos) among the suffragans of Patras. In 869–870, the bishop of Lacedaemon was Theokletos, who participated in the ecumenical council convened by Patriarch Ignatios. His successor, Antony, participated in the council of 879–880 convened by Patriarch Photios. Little is known of the ecclesiastical history of the region thereafter until the arrival of Saint Nikon the Metanoeite in the last three decades of the 10th century. His hagiography gives many, albeit not always reliable, information about the area, including the existence of a Jewish community and still pagan Slavs, on whom Nikon focused his missionary activity.
On 1 January 1083, or thereabouts, the bishopric of Lacedaemon was raised to the rank of a metropolis; its bishop, Theodosios, becoming the first metropolitan. The new metropolis counted three suffragans: Amyclae, Pissa, and of the Ezeroi.
Frankish and second Byzantine periods
Following the Fourth Crusade, most of the Peloponnese was taken over by Frankish Crusaders and became the Principality of Achaea; Lacedaemon itself was occupied, apparently without much resistance, shortly after 1209, as it is not mentioned in the Treaty of Sapienza signed on June that year. In their conquests, the Crusaders retained the existing Greek Orthodox ecclesiastical structure but installed Roman Catholic prelates. Due to the scarcity of the Catholic element but also the few higher clergy available, in 1222–23 several smaller sees, which had had a rather theoretical existence under Frankish rule or were never even occupied after the eviction of their Orthodox bishops, were abolished and amalgamated into the larger ones: thus in 1222, Amyclae was joined with Lacedaemon, followed in 1223 by the see of Helos, which had lain vacant after the Frankish conquest.
Lacedaemon experienced a period of splendour in the mid-13th century, when Prince William II of Villehardouin made it his residence, and began constructing the fortress of Mistra nearby. After the re-establishment of a Byzantine presence in Laconia and the start of warfare between the Byzantines and the Achaeans in 1263, however, most of the inhabitants fled to Mistra. Between 1270 and 1272, Lacedaemon fell to the Byzantines, and in 1278, the last Catholic bishop, Aimon, was moved to the see of Koroni. At the same time, his restored Orthodox counterpart took up his residence in Mistra. Lacedaemon remains a titular see of the Catholic Church, counting 18 holders from 1514 on. It has been vacant since 1967.