(ID #I21275) 
Originally (?) from Messery, Haute-Savoie, he was deacon at Aigle in 1599. He was pastor at Rossinières in 1600, where he and his wife Claudine baptised several children. He was still at Rossinières as late as 1610. He was at Dommartin 1611-1627, during which time his daughter Marie and his son Jean Pierre were noted at least once as sponsors at baptisms. Next, he was pastor at Savigny 1627-1644, where he is believed to have died, and where at least some of his children became established.
A descendant using the spelling of Cornu prepared a genealogy in the early 20th Century, apparently still in private hands.
One internet source gives his wife as Claudine Viret, and places him at Messery-près-Thonon (as pasteur) until 1599, leaving that area as a result of persecution of the Eglise Réformée, then as deacon (or suffragant?) at Aigle. It is perhaps not coincidental that he went to Aigle, as a Cornut family has been known there since at least 1530 (Johannes, a notary, from Samoëns, commissaire for several terriers in the region around Aigle). This information may have come from a professor Benjamin Cornuz of Savigny.
However, it seems more likely that our Pierre Cornut was not in fact a pasteur at Messery, and certainly not officially, in 1599, because the area around Thonon had been reclaimed from Leurs Excellences de Berne by the house of Savoie a few years earlier, and mass abjurations (any holdouts presumably fleeing to Geneva or across the lake to Nyon) had been held in 1598. Among those who abjured, from the village of Nernier, an annex of the protestant parish of Messery, was Claudine, wife of Bernard Cornu, proof that a Cornu family was in the area. Apart from that, the historians tell us that only three protestant ministers are known to have served at Messery before the abjurations: Claude Duret, in 1579; Spectable Jérome Dubois, pasteur of Messery and Nernier, in 1588; and Jean Michaud, in 1589. In that year, Jean Michaud was the only protestant minister in the entire bailliage de Thonon who was allowed to hold services. (Emile Vuarnet, 1898, Messery-Nernier et leurs environs, Mémoires et documents de l'Académie chablaisienne, 12:1-204)
A document at the ACV from the collection of the Association du Vieux-Lausanne (PP 92/498, a single large sheet of paper) bears on one side a very detailed report on the Cornut family, and on the other side, information about the family Chappuis alias Combaz or Delacombaz, suggesting that it might have been part of the collection of documents donated to the Association by the latter family in 1904, or else, as suggested by the inventory of the ACV, possibly an isolated leaf from the Dumur collection of genealogies (ACV P Dumur). The side bearing the Cornut genealogy indicates the information was compiled in 1883, and the script appears consistent with that date. The source was a "cahier manuscrit" in which Antoine Cornut, son of the present Pierre Cornut, had recorded the history of his family and various events of the period, until his death in 1676, with later entries by his descendants. As of 1883, this manuscript was in the hands of "Mr. Daniel Cornuz, fils de Louis et ancien régent à Villars-Bramard". The manuscript itself seems to have disappeared from view. The information presented in PP 92/498 gives brief citations or quotations from other sources as well, possibly detailed enough that we might be able to locate some of them. The family is shown to originate from a certain Wllyamoz Cornut of Samoëns in Faucigny (now in the Département du Haute-Savoie, France), and there are a number of additional citations in the inventory of the ACV for various other Cornut who came from Samoëns in the 16th Century.
Some references for the Classe de Thonon and the history of the reforms in Chablais:
Herminjard, Correspondance des reformateurs.
Hubert Wyrill, Réforme et contre-réforme en Savoie 1536-1679, de Guillaume Farel à François de Sales, Réveil Publications (Lyon, 2001).
Théodore Claparède, Histoire de la réformation en Savoie, 1893.
1880, tome 2 of Mémoires de l'Académie salésienne has lists from the Vatican archives of abjurations compiled by François de Sales in 1598, containing the names of 2300 heads of family in the area around Thonon, pp. 246 ff.
About Louis Viret, minister at Thonon, he was expelled in 1598 and found employment almost immediately as deacon at Payerne, and then 1601 as pasteur at Dompierre, until his death ? in 1614. Several of his son also followed his calling in the Classe de Payerne.
Another family, bourgeois de Nyon, that came from Messery ("Essert-Messery"), is Quiblier, granted bourgeois status in 1605. Franz-Raoul Campiche prepared a "Livre des habitants et bourgeois de Nyon", mentioned in 1946 as a manuscript of 390 folios still in his possession — does it still exist? The best fit seems to be his work catalogued as ACNyon Orange A-02, registre des bourgeois et habitants de Nyon, 1522-1931. Note also Orange C-11.04, Reverdil dossier, actes privés, 1490-1760.

__
|
_Pierre CORNUT ______|
| m 1600 |
| |__
|
_Esdras CORNUT ______|
| (1600 - 1658) m 1620|
| | __
| | |
| |_Claudine _____ _____|
| m 1600 |
| |__
|
|
|--Pierre Antoine CORNUT
|
| __
| |
| _____________________|
| | |
| | |__
| |
|_Jeanne PARIS _______|
(.... - 1632) m 1620|
| __
| |
|_____________________|
|
|__
__
|
__|
| |
| |__
|
_Philibert Emmanuel CORREVON _|
| |
| | __
| | |
| |__|
| |
| |__
|
|
|--Marianne CORREVON
|
| __
| |
| __|
| | |
| | |__
| |
|______________________________|
|
| __
| |
|__|
|
|__

__
|
__|
| |
| |__
|
_Pierre Abraham CORSAT _|
| |
| | __
| | |
| |__|
| |
| |__
|
|
|--Françoise Louise CORSAT
|
| __
| |
| __|
| | |
| | |__
| |
|________________________|
|
| __
| |
|__|
|
|__
__
|
__|
| |
| |__
|
_Daniel CORTESY _____|
| |
| | __
| | |
| |__|
| |
| |__
|
|
|--Abraham Jacob CORTESY
|
| __
| |
| __|
| | |
| | |__
| |
|_Françoise FROSSARD _|
|
| __
| |
|__|
|
|__
__
|
__|
| |
| |__
|
_Jacob (Jaques) Samuel CORTESY _|
| m 1709 |
| | __
| | |
| |__|
| |
| |__
|
|
|--Abraham Jacob CORTESY
|
| __
| |
| __|
| | |
| | |__
| |
|_Jeanne Marie FROSSARD _________|
m 1709 |
| __
| |
|__|
|
|__
__
|
__|
| |
| |__
|
_Jacob (Jaques) Samuel CORTESY _|
| m 1709 |
| | __
| | |
| |__|
| |
| |__
|
|
|--Abraham Jacob CORTESY
|
| __
| |
| __|
| | |
| | |__
| |
|_Jeanne Marie FROSSARD _________|
m 1709 |
| __
| |
|__|
|
|__
__
|
__|
| |
| |__
|
_Jacob (Jaques) Samuel CORTESY _|
| m 1709 |
| | __
| | |
| |__|
| |
| |__
|
|
|--Jean Daniel CORTESY
|
| __
| |
| __|
| | |
| | |__
| |
|_Jeanne Marie FROSSARD _________|
m 1709 |
| __
| |
|__|
|
|__
__
|
_Daniel CORTESY _____|
| |
| |__
|
_Abraham Jacob CORTESY _|
| |
| | __
| | |
| |_Françoise FROSSARD _|
| |
| |__
|
|
|--Jeanne CORTESY
|
| __
| |
| _____________________|
| | |
| | |__
| |
|_Elizabeth CORTESY _____|
|
| __
| |
|_____________________|
|
|__
__
|
_Daniel CORTESY _____|
| |
| |__
|
_Abraham Jacob CORTESY _|
| |
| | __
| | |
| |_Françoise FROSSARD _|
| |
| |__
|
|
|--Jeanne Marie CORTESY
|
| __
| |
| _____________________|
| | |
| | |__
| |
|_Elizabeth CORTESY _____|
|
| __
| |
|_____________________|
|
|__
Protestant minister.