ITS ruined walls have featured in many photographs of Christchurch and its history can be traced back through hundreds of years.

Now a new booklet has been produced focusing on Christchurch Castle that dates back to, perhaps, the 1070s.

It tells of how the castle was built within the Saxon fortified town and not only protected the new Norman lords but had strategic importance in defending the harbour and inland areas from seaborne raiders.

The Manor of Twynham was granted by the Norman king, Henry I, to his friend Richard de Redvers whose son, Baldwin, later lost possession of it.

Baldwin supported Henry's daughter Matilda and her infant son but, in 1147 the manor was seized by Walter de Pinkney, a supporter of Matilda's rival, Stephen.

De Pinkney, with his supporters, however, suffered an ignoble fate when battle-axed to death within the Priory precincts - an event recorded in a painted roundel in the neighbouring Priory (the building of which began in 1094).

Baldwin, or his son, Richard, who succeeded him, built the hall, known as Constable's Hall , writes Michael Hodges in the booklet written on behalf of Christchurch Local History Society.

A total of 68ft long and 24ft wide, the main accommodation for the Lord of the Manor or his Constable was once of great luxury, Mr Hodges writes.

During the ensuing centuries, there were many alterations, including the building of a garderobe (toilet tower) in 1210.

"The date for the massive stone keep on the motte is not certain but research suggests it was during the period 1180-1300," writes Mr Hodge.

It was three storeys high with nine feet thick walls, designed to resist attacks with rams, mines, fire, siege towers and engines and assault by scaling.

"They usually only fell as a result of starvation after a prolonged close siege," he adds.

"During the Wars of the Roses the castle was held for the Earl of Warwick, initially a Yorkist but who changed sides and was eventually killed in 1471.

They were bloody times, for the castle came into the hands of his daughter's husband the Duke of Clarence who was himself murdered.

During the Civil War in the 17th century the castle was held for the King but a detachment of the Parliamentary Army surprised them. "A spirited female, 'the valiant lady captain' also known as 'the valiant oyster woman petitioner' wanted to put up a fight," the booklet states. In 1645, however, a Royalist cavalry leader made an attempt to regain it but the garrison withstood a three-day siege.

Recently, the Mill Stream has given up small cannon balls and under Town Bridge, armour, human bones and some ammunition have been found.

"A ghost in Civil War armour has reputedly been seen in a Bridge Street back garden," Mr Hodges says.

After the conflict neighbouring Corfe Castle was blown up to prevent its reuse in the event of further rebellion.

The same treatment could not be given, however, to Christchurch Castle because of its location in the centre of town.

Instead, the north and south walls of the keep were pulled down and the castle left a ruin.

Christchurch Castle: A Short History by Michael Hodges, Natula Ltd (5 St Margarets Avenue, Christchurch, BH23 1JD. Price £2.50 (postage and packing free).