man Sir (Knt.) Ralph "Radulphus Langton, Rafe de Langton" Langton of Walton and Newton‏‎ #1004‎    , son of Henry Langton of Walton and Newton and Agnes "Agnes de Davenport" Davenport‏.
Born ‎1396, died ‎6 Feb 1431‎, 34 or 35 years
see: 'Lancashire Fines: Henry VI (various dates)', Final Concords for Lancashire, Part 3: 1377-1509 (1905), pp. 123-130. URL: http://www.british-history.ac.uk/report.aspx?compid=52570 Date accessed: 22 March 2010.

The visitation of Cumberland shows that this guy should be Sir Thomas Langton, not Ralph. But that's the only ref suggesting this so leaving as is for now.

http://www.archive.org/stream/historygenealogy02stocage/n569/mode/2up/search/langton

probably the Rafe de Langeton shown here:
“Whereas debate and variaunce is and has been had between Thomas, Bishop of Durham (Duresme), Rauf de Langeton, knyght, Henry of Kyghley, Will of Langeton, parson of the Kirke of Wygan, and James Langeton on the one parte and Laurence de Standisshe, esquire; Alexander his son and heir apparent on the other parte; and also great debate and variaunce and heviness has been hade ymong their ancesteres of the said Rauf and Laurence for divers maters, and one ymonges other as for advowson of the Kirke of Wygan, the quiche the said Rauf and Laurence callen the chappell of Wygan; and for the quiche debate variaunce and hevinesse divers persons of their negh kyn and blode have ben sume woundet and sume slayn, to gret soro and hevinesse to the kyn and frendes of ye said Rauf and Laurence.”
http://standish-history.org.uk/lawrence-de-standish-lord-manor-1418-1434/
William in tree a generation above, along with another james (both of wigan) hard to figure out their exact positions.

Married/ Related to:

woman Alice Unknown‏‎ #1005‎    

Alice, widow of Ralph de Langton
From: 'Lancashire Fines: Henry VI (various dates)', Final Concords for Lancashire, Part 3: 1377-1509 (1905), pp. 123-130. URL: http://www.british-history.ac.uk/report.aspx?compid=52570 Date accessed: 22 March 2010.
http://www.archive.org/stream/historygenealogy02stocage/n569/mode/2up/search/langton

Children:

1.
man Sir Henry Langton Knt. baron of Newton, Lancashire‏‎ #1006    
Born ‎1419, died ‎13 sep 1471‎, 51 or 52 years
sucseeded his father at age of 12.

this henry mentioned here?:
http://www.archive.org/stream/remainshistorica99chetuoftage/2/mode/2up/search/langton

Son of Sir Ralph de Langton.
(www.british-history.ac.uk/report.asp?compid=52568)
13 Aug.1432   Settlementof the action taken by himself, Thomas Langley, Bishop of
                        Durham(q.v.), James deLangton(q.v.) and Henry de Kighley(q.v.)
                        againstLawrence de Standissh(q.v.) and his son, Alexander, deforciants
                        ofthe advowson of the church of Wigan, Lancashire.
                        (ibid.)
2.
man Nicolas Langton of Lancashire‏‎ #2169    

not sure if Nicolas and his son Humprey is the son of this Ralph or another:
1491: "Humphrey son and heir of Thomas Southworth in 1491 received from the feoffees certain lands in Warrington and Winwick, the remainder being to Nicholas son of Ralph Langton. ... The remainder came into operation, for in 1515 Humphrey son and heir of Nicholas Langton sold lands in Middleton, &c., to Sir John Southworth" (Townships Houghton, Middleton and Arbury) Humphrey and Thomas of the Middleton Branch, for Sir John see above.

also this source:
http://books.google.co.uk/books?id=7kEjAQAAMAAJ&pg=PA458&lpg=PA458&dq=voyl+%22langton%22+OR+%22Langeton%22+-lostlangtons&source=bl&ots=VQv5lA98BS&sig=xAeDgq51etM06P63yOPB2TNI8Jc&sa=X&ei=6WYvUOjsOqbJ0QXt24HoDA&redir_esc=y=onepage&q=langton&f=false
3.
man Parson John Langton of Wigan‏‎ #2897‎    
Born ‎1425–1470, died ‎1504 nexty parson appers this year, following Johns death.‎, 33 or 34 years
Assumed to be son of Ralph, seems to be of this generation (or possibly the next).
Rector of Wigan, oc. 1485.
4.
man Jacobi "James Langton" Langton of Lancashire‏‎ #4909‎    

the Jackobi de langeton mentioned here? Does he below as a brotehr of Henry here?

http://www.archive.org/stream/remainshistorica99chetuoftage/30/mode/2up/search/langton

probably the James Langton shown here:
“Whereas debate and variaunce is and has been had between Thomas, Bishop of Durham (Duresme), Rauf de Langeton, knyght, Henry of Kyghley, Will of Langeton, parson of the Kirke of Wygan, and James Langeton on the one parte and Laurence de Standisshe, esquire; Alexander his son and heir apparent on the other parte; and also great debate and variaunce and heviness has been hade ymong their ancesteres of the said Rauf and Laurence for divers maters, and one ymonges other as for advowson of the Kirke of Wygan, the quiche the said Rauf and Laurence callen the chappell of Wygan; and for the quiche debate variaunce and hevinesse divers persons of their negh kyn and blode have ben sume woundet and sume slayn, to gret soro and hevinesse to the kyn and frendes of ye said Rauf and Laurence.”
http://standish-history.org.uk/lawrence-de-standish-lord-manor-1418-1434/