“In anatomical cross section, the stem of Lepidodendron displays an exarch siphonostele surrounded by secondary xylem in ranks.”

“Archaeosigillaria had an exarch actinostele with scalariform and reticulate tracheids.”

“A priest when elected pope by acclamation, he was the last pope to seek approval of his election from the imperial exarch in Ravenna.”

“It appears first in a document of Aistulf of 753 or 754 as a city forming part of the exarchate of Ravenna.”

“When in 739 the Lombards sacked the exarchate of Ravenna and threatened Rome, Gregory appealed to the Franks for aid.”

“Liudprand pressed hard, not only upon the Greek dominions of the exarchate, but also upon Rome.”