This public house is first noted in documents held at Bedfordshire & Luton Archives & Records Service in 1686 in the assize records which noted that "Bletsoe Lane leading from the signe of the Castle in the said Parish to a certaine place in the said Parish called Bletsoe Gapp next adjoyning to a certaine Feild called Milton Field" had been repaired by the inhabitants. This sounds as if it is probably Coplowe Lane which would fit if one assumes the Castle public house was somewhere near Bletsoe Castle.

The other documents are a small run of deeds beginning with sale of the inn by Thomas and Sarah Battison to Essex Archer, who was the publican at the time, in 1720 [SJ1303-1305]. Archer then sold the inn to William Staines, an innholder from Bedford in 1728 [SJ1313-1314] and he held it until his death, his nephew John Staines, a Bedford coal merchant, selling the inn to Lord Saint John in 1783 [SJ1316-1317] when it presumably closed, if it had not done so already.

List of Licensees: note that this is not a complete list. Italics indicate licensees whose beginning and/or end dates are not known:

1720-1728: Essex Archer;
1720-1783: John Staines

List of Sources Held at Bedfordshire & Luton Archives & Records Service:
- HSA1686/S/5: Bletsoe Lane near Castle Inn repaired: 1686;
- SJ1303-5: conveyance of Castle Inn: 1720;
- SJ1313-4: conveyance: 1728;
- SJ1316-7: conveyance: 1783