Walter Erle is the second of the five knights who found themselves incarcerated in 1627. There were only four men in Dorset who didn’t pay the forced loan demanded by Charles I in order to pay for his wars against the Spanish and the French. The other three were Sir John Strangeways, William Savidge and a man called Tregonwell. All four were arrested but none were put on trial as Charles I did not want the controversy of a judge disagreeing with his right to arrest people because they refused to lend him money. Savidge was sent to Clerkenwell Prison whilst the other three, inclusion Erle, were sent to the Fleet Prison.
Oxford educated Erle had also studied law at the Middle Temple which must have been helpful when he became a JP and also Sheriff of Dorset. Charles I’s commissioner in Dorset, the Earl of Suffolk, might reasonably have expected Erle’s support in the collection of the loan but Erle had a reputation as a strong Parliament man ever since his election as an MP – when Charles I dissolved parliament in 1626 in order to avoid the Duke of Buckingham’s impeachment Erle was the MP for Lyme Regis. Thus far his credentials are similar to almost any other member of the gentry. It’s also worth noting that he invested in the Virginia Company.
Erle was one of the five knights who took a case of habeas corpus before the bench which stated that they should be tried by the court to ensure that they had been lawfully detained. Erle was released in January 1628 the judge in the case, Lord Hyde, having accepted the arrest on grounds of matters of state. The full story of Erle’s deletion can be found in Walter Yonge’s diary.
Given his experiences it is perhaps not surprising that Erle was a Parliamentarian. He took part in the English Civil War, notably the Siege of Corfe Castle which was defended by Lady Mary Bankes. Erle and is men took part in the looting and slighting of the castle. Sir Ralph Bankes pursued the matter through the court once peace was restored and although Erle admitted that five or six cart loads of timber and masonry had come into his hands he denied that Bankes should expect restitution.
http://www.historyofparliamentonline.org/volume/1660-1690/member/erle-sir-walter-1586-1665