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de la Pole search dates 1000 to 1700
https://discovery.nationalarchives.gov.uk/results/r?_ep=de%20la%20pole&_dss=range&_sd=1000&_ed=1700&_ro=any&_st=adv
Before you start searching through the almost 700 catalogue entries you need to distinguish the various de la Pole/Pole families so that you know which documents to ignore. A large number of them concern the Suffolk de la Pole family; I noticed some about the Earl of Lincoln, eldest son of the Duke of Suffolk, designated heir to Richard III, who was killed leading a rebellion against Henry VII. You may need to do some historical background reading.
Some documents in National Archives online catalogue Discovery may be in county archives.
As you go back through the documents at The National Archives (TNA), University Special Collections and County Record Offices and Institutions around the Country, one document should lead you to another and related places and people, connected with the family.
Some information contained within many Manuscripts about a Family is unlikely to be online.
The British Library also have a Dept of MSS and the National Libraries and Archives of Wales and Scotland might sometimes acquire items.
One tip, never pick up from where someone else claimed to have got to, you'll often miss a historical background of a family including where the Family lived. Because many landed families lived in several residences during the year and held lands in many different Counties / Countries, which may suggest where possible surviving documents might be held now.
Modern books are sometimes copied from other book/s, or from older books originally written by people wishing to make a grandiose link to a particular person granted Arms and they may have brushed over Manuscripts hidden away in Archives.
Besides Wills, look for Marriage Settlements (before Couples got together) and Transfers of Estates, even modest properties, etc., etc., too.
Don't forget some were Merchants, trading across the Seas, or involved in Crusades going back in history, or worse, even executed, property seized, or sold to pay Tax, etc., or under Papal Law.
Some family documents before and since Henry VIII might even be in the Vatican Archives, or if purchased by them, especially if of Catholic interest.
When families married into another family, property documents and Settlements (apparently missing with one Family) survive as Mss in the other Family Collection, or some documents were acquired by the Family who subsequently took over a Manor or Estate by purchase (to prove a line of ownership).
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Four thousand (4,000) Manuscripts were put up for sale mid 19th Century at the Family Seat house clearance (many for part of our Historic village), collectors from various places purchased them and as these people died parts then got deposited far and wide to Archives across England and Wales.
One author has linked my town to Aston Hall near Birmingham and stated there are no documents. However, there are thousands of surviving Mss documents! He has the wrong Aston Hall, in the wrong county and in the wrong place!
Mark