Ealdor-burh

According to the Old English Dictionary:

-burg;

ealdor-burh

gen. -burge; f. A royal city, metropolis; rēgia arx, metrŏpŏlis :-- On Cantwara byrig, seó wæs ealles his ríces ealdor-burh in civĭtāte Doruvernensi, quæ impĕrii sui tōtīus erat metrŏpŏlis. Bd. 1, 25; S. 487, 19: I. 13; S. 482, 6. Godes ealdorburg God's royal city, Exon. 114 b; Th. 441, 8; Rä. UNCERTAIN 60, 15. ealdor-burh