Legend has it that he is the sire of Justin Morgan. Little to no evidence supports this or the story that he was stolen from Col. De Lancey.
True Briton stood at stud in Lanesboro, MA in 1784, with no pedigree and called Beautiful Bay. In 1785 he was owned by Justin Morgan and stood at stud in West Springfield, MA, still named Beautiful Bay and with no pedigree.
He was then owned by John Morgan Jr., in 1788 and '89. Standing at Springfield, MA., he was advertised as the famous full-blooded English horse, called True Briton or Beautiful Bay, but still no pedigree.
In 1791, he was owned by Selah Norton, and for the first time was given a pedigree, Norton advertising him as True Briton, or Beautiful Bay, got by imported Traveler, dam De Lancey's racer. At this time he was standing in Connecticut. In 1793, he was back in MA, called Beautiful Bay with no pedigree.
In 1794 and '95, he was standing stud at Ashfield, MA, for Selah Norton, who called him Traveler and again gave his pedigree as by Traveler out of De Lancey's racer. This is his last appearance.
—from The Black Hawk or Morgan Family by John H. Wallace