AE´SICA was a Roman frontier castle in the line of Hadrian's rampart, and probably corresponds to the site of Greatchester. It is, however, placed by some antiquaries at the Danish village of Netherby, on the river Esk. It is mentioned by George of Ravenna, and in the Notitia Imperii, and was the quarters of Cohors I. Astorum.
[W.B.D]