Ibstone was described in 1847 in George Lipscomb's "The History and Antiquities of the County of Buckingham" as follows:
IPSTONE is a very small parish, situated on the western verge of Oxfordshire, to which the greater part of those 720 acres comprised in its admeasurement belongs, was anciently surveyed in the Hundred of Desborough, as the land of Hervey the Pope's Legate, holden by him of the King, in capite, as two hides, which are described as situated in Hibestanes. In the Domesday Survey it is particularised as containing five carucates of land; half a hide in the demesne, and two carucates; and seven villeins, having two carucates, to which another might have been added. There was one smith, and four servants, and it was altogether estimated at 4 l. In the time of King Edward, at 100s. This Manor, Tovi, a Thane of King Edward, had previously holden, and could sell it.
In Mr. Langley's Map, the name of this village is printed Ibstone. In Lyson's, the name does not occur at all.
The land-tax assessed for Bucks, only amounted to 47 l. 6s. and the Church, being in Oxfordshire, has left Mr. Langley to mere conjectures respecting the possessions here. The probability of the grant of the estate to Walter de Merton, Bishop of Rochester, as part of the Endowment of Merton College, in Oxford, circ. 1274, is founded upon an Inquisition taken in 21 Edw. I. when it was presented that the Warden and Fellows of Merton Coll. Oxon, held the moiety of Ipstone, in frankalmoign: the estate continuing to be vested in the same jointly, and Sir Christopher Willoughby, Bart. the Lessee.
IPSTONE-HOUSE, formerly the property of Colonel Innes, is chiefly remarkable for the division of the Counties of Oxford and Bucks; a straight line passing through the parlour of the Manor-House, forms the exact boundary of separation between these Counties.