m. (1) Joan Everingham, (2) Cecily Fleming and (3) Margaret Clarell, for the latter two of whom Brice Clagett has found good evidence:

"From: bclagett@cov.com ("Clagett, Brice")"
"Newsgroups: soc.genealogy.medieval
"Subject: Joan Waterton, wife of Lord Welles - a CP contradiction?
"Date: Wed, 29 Dec 2004 17:08:38 +0000 (UTC)

"Until recently the most comprehensive sources for Robert
Waterton (c. 1362-1425), Henry IV's henchman and master
of the horse, and longtime constable of Pontefract (not a
knight, _pace_ RPA p. 758), were H. Armstrong Hall, "Some
Notes on the Personal and Family History of Robert Waterton,
of Methley and Waterton," Publications of the Thoresby
Society 15:81 (1909), and J.W. Walker, "The Burghs of Cam-
bridgeshire and Yorkshire and the Watertons of Lincolnshire
and Yorkshire," Yorkshire Archaeological Journal 30:369 (1931).
Both articles say that the well-known Robert Waterton married
Cecily Fleming and had a son, also named Robert (whom I will
call the pseudo-Robert), who married Joan (Everingham) Ellis,
which younger couple had a son, a third Robert, and a daughter,
Joan (or Cecily), who married Leo, 6th Lord Welles, in 1417.
On this view the well-known Robert made his will (naming wife
Cecily) on Jan. 10, 1424/5 (set forth in Hall pp. 87-88), and his
death was followed "with dramatic suddenness" by that of his
son Robert (of whom nothing else whatever is recorded) on Jan.
17, 1424/5, according to his inquisitions post mortem, CIPM 22:
349-51. Robert's late wife Joan (Everingham) figures in the ipms
because Robert had held by curtesy the manors of Joan's first
husband, Sir William Ellis, and it had to be determined who the
heir of those manors was; it was found that he was Joan's son
Robert Ellis, aged 40 years and more in 1425. Walker's article
(though not Hall's) recognizes that the Robert of the ipms had
a later wife, Margaret (Clarell) Fitzwilliam, who survived him.

"The age of Robert Ellis in 1425 is a strong pointer towards the
truth. Since he was born by 1385, his mother (Joan) would have
been a full generation older than her second husband if that
husband (the pseudo-Robert) was the son of Robert c. 1362-
1425. And in fact Joan appears to have been born in 1362/3; see
CP 5:193. Both the chronology and Occam's razor require that
the pseudo-Robert be expunged. One will, one death in Jan.
1424/5, one set of ipms = one Robert, who married (1) Joan
(Evereingham) Ellis, (2), before 1407/8, Cecily Fleming,
(3), in 1422 or 1423, Margaret (Clarell) Fitzwilliam. While Robert's
will calls Cecily his wife, it does not say that she was then living;
if anything it implies the contrary, providing only for prayers and
memorials for Robert and Cecily. If it be objected that the will does
not mention Waterton's living wife, Margaret, it does not mention
his two children either; the only persons named in the will are the
executors, supervisors and witnesses.

"Various records, mostly cited by Walker, show that Waterton
married Cecily before 1407/8 and was still married to her in 1412; she
is said to have died in 1422, though I don't know what the proof of that
is. Waterton's son Robert, aged 16 in 1425, was clearly hers. It seems
less clear whether Joan or Cecily was the mother of Lady Welles, since
we seem to lack a record of her age at any time. (Lady Welles is
usually referred to cautiously as Joan or Cecily; if she was Cecily
that would strongly indicate that her mother was Cecily also. But,
while more-or-less original sources support both versions, in my
opinion the best are four ipms of John, 5th Lord Welles, CIPM
21:306-07, which uniformly called her Joan.)

"The sketch of Robert Waterton in the new ODNB is in accord with
the above analysis, though it does not supply its reasoning or
discuss conflicting views."
______________________________________________________

His heir was his son Robert, aged 16 at his death.

In the Everingham article he is an armiger but in the Welles article he is a knight; from the IPM quoted in the Everingham article, I think he was no knight.
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Did he marry a Margaret Waterton?  (Garter book)

Did he have a descendant Mary, dau of a Robt Waterton of Waterton, which Mary m. Robt Payne of St Neots, Hunts and whose son Robert Payne was living in 1613?  (Hunts Visitation, p. 64.)
_______________________________________________________

Here's an interesting snippet on the Watertons:

There is abundant information in many forms that Joan de Everingham had a son Robert by her second husband, Sir Robert Waterton. He in turn married Jane, daughter of John Meeres of Kirton-in-Holland, Lincs., and had a son Sir Thomas Waterton who it is said, was briefly Master of the Horse to King Henry VIII. After the death of Jane Meeres (possibly in her childbirth), he married Beatrice, daughter of Thomas, 8th Lord Clifford, but had no issue by her. Our line appear to have been quite diligent in maintaining the records as much of this fell into my lap as it were, when it was realised by parents, that I had developed an interest. You also appear to have picked up on another anomaly that has regularly been promulgated in various peerages, that of Jane (Joan) Waterton who married Loinel, 6th Lord Welles. She was in fact, sister-in-law of Joan de Everingham and daughter of Robert Waterton (1st High Steward of the Duchy of Lancaster & Constable of Pontefract Castle) who married the niece of Richard Fleming, Bishop of Lincoln and was sister to Robert Fleming, Dean of Lincoln. Her name was Cecily and she was daughter to Sir Robert Fleming of Woodhall Methley and became, in her issue, the heiress of her father. In turn, her daughter Jane (that married Lord Welles) became heiress of her mother. Had Jane been grandaughter, not daughter of Robert Waterton, the Welles' would no doubt have been counted among the coheirs of the Everingham barony. This they never were and such is borne out by a close examination of the dates involved, which mitigate against.  As to the two references you cite on Waterton, I have had both for thirty years and more and much as I respect the work that has gone into Walkers pedigree, there are some fundamental problems with certain areas. The most extensive work to be done on the family was at the behest of Edmund Wateron of Walton Hall FSA (1830-1887), which was commissioned privately, but alas we do not know the name, or names, of the researchers. One suspects, with his predelictions, that Edmund himself conducted much of it and there is always the suspicion that he allowed himself too much leeway in certain areas.
_______________________________________________________

A later statement by Brice Clagett:

"From: bclagett@cov.com ("Clagett, Brice")
"Newsgroups: soc.genealogy.medieval
"Subject: Robert Waterton and his daughter Joan, Lady Welles
"Date: Wed, 5 Jan 2005 17:55:55 +0000 (UTC)

"Re James Cummings' post of yesterday:

"Chris Phillips has convinced me that if (as seems clear on
chronological grounds) Sir Robert Waterton was son of
Robert (d. 1425) by Cecily Fleming, then Joan Lady Welles
must have been also, for if they were half-siblings her heirs
would not have inherited from Sir Robert under the rule
excluding relatives of the half-blood.

"By virtue of the same rule, even if Sir Robert had been the
son of Joan Evereingham, (1) he would not have inherited
anything from Robert Ellis, (2) the Ellis heirs would not have
figured in Sir Robert's ipm."

So the primary question is whether Robert Waterton was the son of Cicely Fleming.

The reaoning that Robert might be the son of Cecily is that he was young at his father's death in 1425 so must have been born after their marriage in 1407.  As yet I have not seen confirmation of this so am reserving judgement.
______________________________________________________

Brice Clagett on 14th March 2005 wrote:

"The ipm of Robert Waterton the father, taken in 1425, CIPM 22:349,
says that Robert the son was aged 16. We know that Cecily was the
father's wife by 1408. This doesn't leave much room for error, but
it's the best we seem to have."

Looks good to me!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fascinatingly the 1584-5 Yorks visitation, p. 312, has a Robert Waterton of Everingham who m. “Joan, or Elizabeth, dau. to Sir John Savile, widow of ... Ellis”.  They are recorded as having a son Robert who also had a son Robert.
_____________________________________________________

C T Clay in a footnote on p. 9 of his “Early Yorkshire Families” says that a Richard son of John Waterton mattied Constance Assenhull, dau. of Joan de Burgh and on the Burghs there is a very long article “The Burghs of Cambridgeshire and Yorkshire” by J W Walker in the Y.A.J., xxx, 311-419  and in which see p. 348.

Feb 2007, TFPL: I have found Walker’s article, which is on both the Burghs and the Watertons and is indeed some 100 pages of detailed reporting.  I hope to make a copy of it eventually but this will take time; it’s excellent anyhow, apart from not sorting out the last generation of wives.
_______________________________________________________________________

Barry of six ermine and gules, three crescents sable - Twysden.