By the 17th century, Filkins was becoming the most economically developed part of the parish. This is reflected in the Churchwardens' Accounts which have a separate page for Filkins entries, and by the fact that instead of a Vicar's Warden and a People's Warden, there was a Broadwell and a Filkins Warden. Similarly there were two Surveyors of the Roads for Broadwell, but four for Filkins - two for Nether and two for Upper.

At the beginning of the 18th century, most of the parish was owned by Lord George Hamilton, one of Marlborough's generals. Perhaps Hamilton and the Duke shared a bottle or two over their old campaign maps somewhere between Broadwell and Blenheim. Later, after the estates had passed to Hamilton's son-in-law, the Earl of Inchiquin, the old Manor House in Broadwell was destroyed by fire about 1740. Only the stone gate piers remain. The Inchiquins moved to a smaller Jacobean house at Broadwell Grove. In 1804 William Hervey, already a large land owner bought the 2000 acre Broadwell Manor and set about adding to it with further purchases in Filkins and Broughton Poggs. He was induced "by the local gentry" to buy Filkins Hall because they had heard that the chartist Fergus O'Conner was interested and they did not want another of his radical Minster Lovell allotment schemes here. Hervey employed the well known Architect/Builders Richard Pace & Son to replace the Bradwell Grove house, (which was "too gloomy to be pleasing"), with a large Gothic pile.

Probably because his seat was no longer in the centre of the parish, and also because he might not have liked the growth of dissenters' meeting houses (one of the first of which, a Baptist chapel, near Broughton Mill, is now a garage), Hervey determined that each of the hamlets should be separated parishes. He started with Holwell and in 1842 applied to the diocese to rebuild the existing "ancient and ruinous edifice". Having promised 100 free seats, he recruited 100 villagers to petition the Bishop. In 1845 he got his way and rebuilt the chapel, adding a burial ground at this own expense. The curate of Broadwell, Charles Astley, became the first Vicar of Holwell.

There is evidence to suggest that Hervey reused the original windows in his building, and generally concocted a somewhat rustic and unsatisfactory structure. In any event Hervey's new church did not last long, for it was itself pulled down by the next squire, W H Fox, and replaced in 1894.

After this Holwell episode, William Hervey turned his attention to Filkins, and in 1851 an application was made to the diocese to allow a church here. It was to seat 120 adults and 50 children and the cost was estimated at œ900. There is now no plan, but it was probably a simple Cotswold barn-like construction with a traditional stone roof. Unfortunately for Hervey and the other originators of the plan, George Street, the Diocesan architect was asked to comment.

He rather sniffily observed that there was no architect's name on the plans and concluded that designer and contractor were one and the same. "It is clear", he wrote, "that one of the very important parts of an architect's function, the superintendance of his designs, can only be impartially exercised best when there is no personal interest in the matter". (One wonders how designer/builder Richard Pace had so ably managed the excellent stable block at Filkins Hall). Street went on, however, to lambast the particulars of the design, which he said "were very poor". The roof timbers were "far too weak for the 25 foot span" while "the roof covering [was] of the heaviest kind". The bell-tower opening was too small for the proposed bell, it would be impossible to kneel between the crowded pews, no gutters were shown, and the vestry apparently had a flat roof.

Street finished his report with "the fact is the plan is far from good and not cheap". So wide a church with a large poor roof can never look really well and is practically as expensive as a church consisting of a nave and one aisle would be. Not surprisingly the church did not get built.

Three years later, in 1855, further plans were submitted for a larger church designed by G E Street himself. It would have a north aisle, a lighter weight roof, a larger bell turret, and gutters.

Meanwhile William Hervey busied himself with the paperwork. In February 1855, by an Order in Council, it was ordained that with the next change of Broadwell incumbent, Filkins would be separated from the parish and attached to Broughton Poggs. A certain amount of behind the scenes activity must have gone on: before the end of the year, Thomas Goodlake, the Vicar of Broadwell, left to become Vicar of Broughton Poggs cum Filkins.

The new church in Filkins was completed, and consecrated to St Peter by Bishop Samuel Wilberforce of Oxford, the son of the anti-slaver William Wilberforce. The ceremony took place on Easter Tuesday 1857 and was described in the Oxford Church Calendar. Bishop Wilberforce, who was so persuasive an orator as to be generally known as "Soapy Sam" , preached from a text from St John: "And when he had so said, he shewed unto them his hands and his side...". There were thirty clergy present including the Bishop of Jamaica who was present perhaps as a guest of William Hervey who owned several West Indian sugar plantations. Sadly Mr Hervey himself, at over 80, was too ill to attend. Later the Vicar, Mr Goodlake, hosted a dinner for the builders, and the village children paraded round the church singing hymns.

In 1864 the break-up of the old parishes was completed when Filkins was made into an autonomous Parish, with the Bishop of Oxford as Patron. Robert Price became the new Vicar. The indefatigable William Hervey died in May 1863, just too soon to see this final development.