Complex sentence: Leo II was proclaimed Caesar in October, 473 and effectively became the designated heir to the throne by virtue of being the closest male relative of Leo I. On 18 January 474, Leo I died of dysentery.
Split into simpler sentences: Leo II was proclaimed Caesar in October, 473 and effectively became the designated heir to the throne. By virtue of being the closest male relative of Leo I. On 18 January 474, Leo I died of dysentery.