By the 1240s, the Stewarts appear to have gained lordship in the Firth of Clyde and Cowal, whilst Alexander II, King of Scotland attempted to extend royal authority into Argyll and the Isles.
It is in the context of this Scottish encroachment into Argyll that Dubhghall first appears on record, in an appeal to Pope Innocent IV for papal protection in 1247.
Charter evidence dating to 1261 and 1262 reveals that Dubhghall resigned the Clann Suibhne lordship into Walter Stewart's hands.
The fact that some members of the kindred were unwilling to subject themselves to Stewart domination is evinced by the ensuing career of Dubhghall's nephew, Murchadh Mac Suibhne.
[16] The succeeding son of this couple is further stated by this source to have been named Dubhghall, and is elsewhere attested as an historical landholder in Argyll.
[37] The original site seems to have consisted of two free-standing buildings: a two-storey residence with a lord's hall, and a single-storey chapel.
[50] The family's authority over the island is specifically evidenced by a charter of Alan of the church of Kingarth and the entire parish on Bute to Paisley Abbey.
[62] Charter evidence reveals that by about the time of the latter's death in 1241, Cowal had been brought under Stewart overlordship, and Scottish royal authority was further expanding into Argyll.
[63] Specific early evidence of this encroachment is preserved by a grant of Laghmann mac Maoil Choluim of the church of St Finan (Kilfinan) to Paisley Abbey in 1232×1241.
[85] The westward extension of Scottish royal authority may account for the records of Dubhghall and the monks of Iona requesting papal protection.
[93] Upon learning of the catastrophe, Cecilía's father, Hákon Hákonarson, King of Norway, immediately sent Eóghan Mac Dubhghaill to temporarily take up the kingship of the Isles on his behalf.
[98] In the course of the campaign, Alexander II demanded that Eóghan renounce his allegiance to Hákon, and ordered him to hand over certain mainland and island fortresses.
[110][note 12] Dubhghall is elsewhere stated to have granted Walter Stewart his lands to be held as a "free barony" for two-thirds of a knight's service in the king's army.
[114][note 13] One of these transferred territories is recorded as "duabus Ungyns MacCrunnel",[116] a place name that corresponds to Dubghall's title "lord of the land of Macherummel", used by the papal protection granted to Dubhghall in 1247.
[133] The creation of a Stewart lordship in the region may have been undertaken in the context of extending Scottish royal authority into Argyll and the Isles.