Warwick and what was left of his army met up with Edward's army on 23 February near Burford - Warwick territory. They must have had a fairly interesting talk about political and military strategy, and at least at first they must have been uncertain about whether or not the Lancastrians had taken London.
The Yorkist march on London was probably inevitable in any case, but one imagines that the departure of Queen Margaret and the Lancastrian army to the north was not exactly bad news. Edward entered London on 28 February (or 26 or 27, depending on which source you choose to believe) and was very well received; he may have chosen to overlook the fact that the city fathers had been preparing to proclaim him a traitor only a few days earlier. Such are the strange chances of politics, although it appears that the bulk of the city population were Yorkist or Warwick supporters in any event.
Over the next few days there was a concerted propaganda exercise. The nub of it was that Henry VI had reneged on the settlement that had been enshrined in the Act of Accord. Now, given that poor Henry was practically a cipher by this time, controlled by whoever had hold of him, this was a little harsh on the King. However, some pretext was needed to justify Edward taking the throne and in the circumstances this spin is understandable.
Many of the citizens were gathered at St.John's Fields Clerkenwell on Sunday 1 March, where they were addressed by clerics, probably Thomas Bourchier the Archbishop of Canterbury and certainly Warwick's brother, George Neville, Bishop of Exeter. The crowd, reacting no doubt to some excellent speeches, rejected Henry VI and called for Edward of York to take the crown.
This 'election' by the people was reported to Edward and supported by the (relatively) few nobles present, of whom the most important were the Duke of Norfolk and Warwick himself.
Edward, still only eighteen years old, was apparently more than happy to take the crown on these terms. He almost certainly thought it was his by hereditary right in the first place. Now, unlike his father a few weeks earlier, he had Warwick onside.
On Wednesday 4 March there was a slightly more formal mass meeting outside St.Paul's Cathedral at which Edward himself was present. The Bishop of Exeter preached a sermon which dwelt on Edward's ancestry and other good points. Would the people have him as their King? Those people present (less than a representative sample it must be granted) said 'Aye!'
Edward accepted the job at once and went in procession (probably a very long and undignified one) to Westminster where he sat on the King's Bench and formally took possession. He was to date his reign from this day.
This was all very 'revolutionary' - but in such circumstances law offers little guidance. Edward was the legitimist King, Henry the statutory one, and you paid your money and took your choice. I don't think there was a 'right' or a 'wrong'.
There was of course no time for a coronation. Henry and his supporters were in the north and Edward IV's first task was to march north, defeat them in battle, and so make his kingship 'real'. The London merchants showed their faith in his cause by lending him large sums to meet the cost. It was to prove a sound inverstment.