The term Basilika or 'Basilica' (Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

: ) refers to a code of laws issued by the Eastern Roman emperor Leo VI the Wise

Leo VI the Wise

Leo VI, surnamed the Wise or the Philosopher , was Byzantine emperor from 886 to 912. The second ruler of the Macedonian dynasty , he was very well-read, leading to his surname...

 (reigned 886-912). Written entirely in Greek, the 'Basilica', in 60 books, adapt the 6th-century Justinian code to the conditions of the 9th- and 10th-century Empire, and include laws issued by Leo VI and his predecessor Basil I

Basil I

Basil I, called the Macedonian was a Byzantine emperor of probable Armenian descent who reigned from 867 to 886. Born a simple peasant in the Byzantine theme of Macedonia, he rose in the imperial court, and usurped the imperial throne from Emperor Michael III...

.

Sources

• Vasiliev, A. A.
  Alexander Vasiliev
  Alexander Alexandrovich Vasiliev was considered the foremost authority on Byzantine history and culture in the mid-20th century. His History of the Byzantine Empire Alexander Alexandrovich Vasiliev (1867-1953) was considered the foremost authority on Byzantine history and culture in the mid-20th...
  
  History of the Byzantine Empire, 324-1453. Second edition. Madison, 1952 (pp. 342–3)