The evolution of the English language over a 1,000-year time span traces back to the 5th century when England was invaded by different tribes, including the Angles, Jutes, Saxons, and Frisians. Their languages produced what we know today as Anglo-Saxon or Old English, which sounded similar to German. In the 8th, 9th, and 10th centuries, invasions by the Vikings of Denmark, Norway, and Sweden brought another form of the same Germanic language, Old Norse, which mixed with Old English.
In the year 1066, French forces led by William the Conqueror conquered England. Over the next 300 years, thousands of French words entered the English language, especially those related to governance and food. During the English Renaissance, many Latin-based words also entered the language, partly due to English poets, writers, and playwrights. Shakespeare, for instance, wrote plays set in Italy, such as "Romeo and Juliet," "The Merchant of Venice," and "Julius Caesar."
By the mid-1500s, a modern-day English speaker would be able to communicate with some patience and concentration. While there would be some archaic pronunciations, shifting meanings, and evolving figures of speech, the language overall would be recognizable.