Kingdom, capital, population (note 1), [language]
Brittany (not shown) Roazon (Rennes) 2,515,600 [Breton]
Connacht Galway 430,726 [Irish]
Cornwall Truro 439,000 [Cornish]
East Anglia Thetford 1,939,600 [English]
Essex London 6,674,289 [English]
Isle of Man (note 2) Douglas 65,000 [Manx]
Kent Canterbury 5,064,841 [English]
Leinster Dublin 1,851,134 [Irish]
Mercia Tamworth 11,171,437 [English]
Munster Cashel (note 3) 1,019,694 [Irish]
Northumbria Bamburgh (note 4) 12,825,800 [English]
Scotland Edinburgh 5,145,722 [Irish]
Sussex Chichester (note 5) 2,201,274 [English]
Ulster Belfast 1,830,641 [Irish]
Wales Cardiff 2,807,200 [Welsh]
Wessex Winchester 5,877,881 [English]
1. Based on existing population of the region. However, this may be misleading in the case of Kent and Essex, as it is unlikely that London would be such a huge bloated metropolis if it were merely the capital of Essex, instead of the overpopulated capital of an overpopulated country.
2. Scottish protectorate.
3. There could be a case for moving the capital to the country town of Tipperary, given that the other Irish kingdoms all have county boroughs as their capitals, but on the whole I prefer to respect the historical traditions associated with the stone of Cashel.
4. Or York, both have an equally valid historical claim.
5. Moved from Selsey in the 13th century.