Patrick is said to have had twelve sons who came to maturity, but all pre-deceased him. Only the children below are known. A reference in Stewarts of the South: Glenbuckie Branch X seems to infer that other than Robert, below, all his sons were illegitimate. Presumably, had any of these sons been legitimate then they would have inherited Glenbuckie. Patrick inherited Glenbuckie and then died. His brother Duncan succeeded him in the estate. From below it seems that Patrick's son Robert may have been an intervening laird who may also have died young and that the estate of Glenbuckie passed from Patrick briefly to his son Robert and then to Patrick's brother Duncan (http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&db=ryk%5Fbrown&id=I1891)