Richard, Duke of York and his ally, Richard Neville, Earl of Warwick defeated the Lancastrians under Edmund Beaufort, 2nd Duke of Somerset, who was killed. York captured King Henry VI of England and had himself appointed Constable of England.
The second Battle of St Albans was fought February 22, 1461. With the defeat and death of the Duke of York the previous December (at the Battle of Wakefield, and York's son and heir busy in the west (where the Battle of Mortimer's Cross was fought a few days before the engagement at St Albans), the way was clear for the Lancastrians (lead by Queen Margaret ) to march south towards London, pillaging and sacking as they went.
They were intercepted near St Albans by forces commanded by the Earl of Warwick. Warwick had his men set up an array of defenses, including ditches and spikes, but they were surprised and defeated before these were complete.
The Lancastrians captured King Henry, who supposedly spent the battle sitting under a tree, singing. But they did not press their advantage by marching south to London. The reasons are not clear; it may be that their reputation for pillaging had preceeded them as the Londoners would not open their gates.