Ranulf enlisted the help of Robert, 1st Earl of Gloucester to retake the castle and succeeded when King Stephen surrendered to him at Lincoln.

He was the son of Ranulf Meschin, 3rd Earl of Chester and Lucy of Bolingbroke, who were both significant landowners with considerable autonomy within the county palatine.

In the second Treaty of Durham (1139), Stephen was even more generous to David, granting the Earldom of Northumbria (Carlisle, Cumberland, Westmorland and Lancashire north of the Ribble) to his son, Prince Henry.

By this time Matilda, named as the future Queen by her father Henry I, had gathered enough strength to contest Stephen's usurpation, supported by her husband Geoffrey of Anjou and her half-brother Robert of Gloucester.

He and his half-brother William de Roumare sent their wives to visit the constable's wife there and then arrived (dressed in ordinary clothes and escorted by three knights), apparently to fetch the ladies.

Ranulf managed to escape to his earldom, collect his Cheshire and Welsh retainers and appeal to his father-in-law Robert of Gloucester, whose daughter Maud was still besieged in Lincoln, possibly as a deliberate ploy to encourage her father's assistance.

The queen's forces surrounded the army of the empress, commanded by Robert, who was captured as a result of deciding to fight his way out of the situation.

Ranulf demonstrated his goodwill by helping Stephen to capture Bedford from Miles de Beauchamp and bringing 300 knights to the siege of Wallingford.

Ranulf's opponents counselled the king that the earl might be planning treachery since he had offered no hostages or security and could easily be ambushed in Wales.

Stephen contrived a quarrel with Ranulf at Northampton, provoked by an advisor who told the earl that the king would not assist him unless he restored all the property he had taken and rendered hostages.

It was then agreed that the earl should be released, provided he surrendered all the royal lands and castles he had seized (Lincoln included), gave hostages and took a solemn oath not to resist the king in future.

Ranulf, arrested in contravention of the oath which the king had sworn to him at Stamford, revolted as soon as he regained his liberty and "burst into a blind fury of rebellion, scarcely discriminating between friend or foe”.

He came with his army to Lincoln to recover the city but failed to break into its north gate and his chief lieutenant was slain in the fighting.

The southern portion of the honour of Lancaster (the land between the Ribble and the Mersey) was conceded to Ranulf, who in return resigned his claim on Carlisle.

Henry, whilst trying to escape south after the aborted attack on York, was forced to avoid the ambushes of Eustace, King Stephen's son.

That year, whilst Ranulf was a guest at the house of William Peverel the Younger, his host attempted to kill him with poisoned wine.