Old English, Middle English, Early Modern English, Modern English
My opinion as to the chronology of English
About 500 to 11th century — Old English, as spoken by the Anglo-Saxons. Many inflectional endings. Masculine, feminine, and neuter cases. Virtually incomprehensible to the modern reader. Sounds like a dialect of German.
11th century to about mid-fifteenth century — Middle English. Much less inflections. Only masculine and feminine cases. Many regional dialects. Eventual disappearance of the letters yogh and thorn (Chaucer used them inconsistently). Numerous borrowings from French. More comprehensible to the modern reader than Old English. Still sounds German. Chaucer wrote in the London dialect of Middle English.
Early Modern English—About mid-fifteenth century to the Restoration. Great Vowel Shift. Much more comprehensible to the modern reader than Middle English. Sir Thomas Wyatt, Shakespeare, King James Version of the Bible was written in Early Modern English.
Modern English—from about 1660 to present (i.e., from the Restoration. Much more comprehensible to the modern reader than even Early Modern English. Dryden, Milton, and people after him wrote/write in Modern English.