THIRD PARAGRAPH 
 In the third paragraph "However, his assassination caused a two decade-long war with Sassanid Persia which exhausted the Empire's resources and contributed to major territorial losses during the Arab–Byzantine wars of the 7th century." is quoted, while I understand the discursive language chosen to link Arab-Byzantine wars it is much more appropriate to link the Muslim conquest page at this juncture, because this page references not just the Arab-Byzantine wars but the effects the Muslim conquests had on the great ancient powers following a more complete encyclopedic approach. So the third paragraph should read thus, "However, his assassination caused a two decade-long war with Sassanid Persia which exhausted the Empire's resources and contributed to major territorial losses during the Muslim conquests of the 7th century." hyper-linking Muslim conquest to the Muslim conquests page rather than just the Arab-Byzantine wars. 

 Also, the term "progressive annexation" completely misses the realities of the monumental conquests undertaken by Mehmet II and the Ottoman's as a whole; terminology that better describes the facts of the period should be used. Perhaps a simple adjective like "violent annexations" or "military conquests" would be more appropriate and better clarify the true state of affairs in the 15th century.   

 EXPLANATION OF ROMAN TO BYZANTINE:  
 An explanation of the evolution from Roman Empire to Byzantine Empire should be detailed in this article: I would provide a paragraph explaining what it meant to be Roman and how Justinian I (527-565) can deemed the last great Latin Roman Emperor and Heraclius (610-641) can be deemed the first great Greek Roman Emperor, this distinction and time frame will shape the understanding of readers in a manner that provides an easily understood example of the differentiation between east and west and the changing nature of the empire from Latin to Greek as a whole.