Legio was a Roman Catholic titular see in the former Roman province of Palestina Secunda, which was suffragan of Scythopolis
It figures for the first time in a Latin episcopal notitia, dating probably from the eleventh century, where it is given under the name of Legionum, between the Bishoprics of Diocæsarea and Capitolias (Tobler and Molinier, "Itinera Hierosolymitana", I, Geneva, 1880, 343). If, however, we consult the Greek Notitiæ Episcopatuum, of which the Latin is only a translation, we find in that place, not Legio, but Maximianopolis. The see of Legio is, therefore, identical with Maximianopolis.
In the Middle Ages both cities were identified, being near neighbours, though really distinct places in the same see. Legio became Lajjun, well known in the Bible and in history under the name of Megiddo.
Read more about Legio: Recent Research