Justiciar Definition: An obsolete judicial position of English nobility; that of chief justice of the realm. "An officer instituted by William the Conqueror, of high importance .... a lord chief justice. He presided in the King's Court and also in the Exchequer and his authority extended over all courts. He was ex officio regent of the kingdom in the King's absence."1 The formal title given to England's justiciar was Capitalis Justitiarius Angliae. Philip Basset (1185-1271) was Henry III's justiciar and the last to hold the post. REFERENCES: Duhaime, Lloyd, Odo of Bayeux, First Justiciar of England (1038-1096) Categories & Topics: Ancient Common Law Dictionary Dictionary of Latin Law Terms Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!