Aspron Trachy - Alexios III Angelos Constantinopolis, IC-XC ΚΕ ΡΟΗΘΕΙ obverse, ΑΛΕΖΙΩ ΔΕϹΠ Ο ΚΩΝΤΑΝΤΙ reverse

Alexios III came to power by blinding and deposing his own brother, Isaac II, in 1195 — a coup that would set in motion the catastrophic chain of events culminating in the Fourth Crusade's sack of Constantinople in 1204. His eight-year reign was defined by fiscal collapse; he famously stripped bronze from imperial tombs at the Church of the Holy Apostles to meet military expenses. The billon content of aspron trachea issued under his name had degraded so severely by this period that the term "billon" is generous.