Note 50 — Chapter II · THE FORMATION OF THE KINGDOM OF ENGLAND. 449–975.
Reading edition
The exact boundary started from the Thames, along the Lea to its source, then right to Bedford and along the Ouse till it meets Watling-Street, then along Watling-Street to the Welsh border. See Ælfred and Guthrum’s Peace, Thorpe’s Laws and Institutes, i. 152. This frontier gives London to the English; but it seems that Ælfred did not obtain full possession of London till 886. See Earle’s Parallel Chronicles, p. 310.