Richard Marshal, Third Earl of Pembroke, who holds lands in Longueville, France, in Wales and also in Ireland, has come to the fore as the leader of the baronial party, and the chief antagonist of the foreign friends of King Henry III, notably the Poitevins Peter des Roches, Bishop of Winchester, and Peter de Rivaux, an influential courtier.

Fearing their treachery, he had refused in August 1233 to visit King Henry III at Gloucester, and King Henry had declared him a traitor.

Hubert de Burgh in 1233 escapes from Devizes Castle and joins Marshal’s rebellion.

A truce is reached in March 1234 between the king and Richard Marshal, the condition of which is the removal of Peter de Rivaux from court.

Meanwhile, however, conflict has broken out in Ireland between Marshal's brothers and some of the king's supporters.

Hostilities follow, and …

…Richard makes an alliance with the Welsh prince Llywelyn the Great.

He crosses from Wales to Ireland, where Peter des Roches had allegedly instigated his enemies to attack him.

Marshal is overpowered and wounded at the Battle of the Curragh by forces led by Maurice FitzGerald, Justiciar of Ireland, and on April 16, 1234, dies of his wounds while being held prisoner.

Marshal's popularity also means that his death is mourned in England, while the Poitevins—who are rumored to have instigated the Irish war—fall further into disregard.

Peter des Rivaux, in effect Henry's chief minister from 1232 onward, has held positions in the king's household and had been installed as sheriff (or granted the power to appoint sheriffs in his stead) for some twenty-one shires.

His administration includes Stephen Segrave (high sheriff of several counties), Henry of Bath (high sheriff of Gloucestershire), Robert Papelew and Brian de Lisle, and has achieved a centralization under his hand of much royal revenue.

He also holds the office of Lord High Treasurer from January 14, 1233, but falls dramatically from power in 1234, consequent on the death of Richard Marshal, Third Earl of Pembroke, which is attributed to machinations of Peter des Roches.

For a time, Peter de Rivaux and associates are proclaimed traitors.

Some partial rehabilitation follows.