Definition: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
Input: This era coincided with the Medieval Warm Period (800 1300) and stopped with the start of the Little Ice Age (about 1250 1850).

This happened at the same time with the Medieval Warm Period (800-1300) and ended at the Little Ice Age (1250-1850).