In 1327, the Scots invaded northern England and defeated the English at Stanhope and Weardale. Soon afterwards, the Scots invaded Ulster in Ireland. Isabella and Earl Mortimer of March could not raise a force on such short notice and agreed to make peace on Bruce's terms. In May 1328 Isabel and Mortimer agreed in the treaty that they in the name of young Edward III "renounced all pretensions to sovereignty" to Scotland; and Joanna (six years of age), sister of Edward III, was promised in marriage to David (four years of age), son of Robert Bruce. In the quitclaim of Edward III of 1328, one can see the treaty mentioned: The Scottish borders set by Alexander III "shall remain for ever to the eminent prince Lord Robert, by the grace of God the illustrious king of Scots, our ally and dearest friend, and to his heirs and successors, divided in all things from the realm of England, entire, free, and quit, without any subjection, servitude, claim, or demand."
Also, as part of the treaty, Edward III agreed to return the Stone of Destiny to Scotland. However, this was never done.
See Also: Wars of Scottish IndependenceThe Full text
To all Christ's faithful people who shall see these letters, Edward, by the grace of God, King of England, Lord of Ireland, Duke of Acquitaine, greeting and peace everlasting in the Lord. Whereas, we and some of our predecessors, Kings of England, have endeavoured to establish rights of rule or dominion or superiority over the realm of Scotland, whence dire conflicts of wars waged have afflicted for a long time the Kingdoms of England and Scotland: we, having regard to the slaughter, disasters, crimes, destruction of churches and evils innumerable which, in the course of such wars, have repeatedly befallen the subjects of both realms, and to the wealth with which each realm, if united by the assurance of perpetual peace, might abound to their mutual advantage, thereby rendering them more secure against the hurtful efforts of those conspiring to rebel or to attack, whether from within or without: We will and grant by these presents, for us, our heirs and successors whatsover, with the common advice, assent and consent of the prelates, princes, earls, barons and the commons of our realm in our Parliament, that the Kingdom of Scotland, within its own proper marches as they were held and maintained in the time of King Alexander of Scotland, last deceased, of good memory, shall belong to our dearest ally and friend, the magnificent prince, Lord Robert, by God's grace illustrious King of Scotland, and to his heirs and successors, separate in all things from the Kingdom of England, whole, free and undisturbed in perpetuity, without any kind of subjection, service claim or demand. And by these presents we denounce and demit to the King of Scotland, his heirs and successors, whatsoever right we or our predecessors have put forward in any way in bygone times to the aforesaid Kingdom of Scotland. And, for ourselves and our heirs and successors, we cancel wholly and utterly all obligations, conventions and compacts undertaken in whatsoever manner with our predecessors, at whatsoever times, by whatsoever Kings or inhabitants, clergy or laity, of the same Kingdom of Scotland, concerning the subjection of the realm of Scotland and its inhabitants. And wheresoever any letters, charters, deeds or instruments may be discovered bearing upon obligations, conventions and compacts of this nature, we will that they be deemed cancelled, invalid, of no effect and void, and of no value or moment. And for the full, peaceful and faithful observance of the foregoing, all and singular, for all time we have given full power and special command by our other letters patent to our well-beloved and faithful Henry de Percy our kinsman, and William de la Zouche of Ashby and to either of them make oath upon our soul. In testimony whereof we have caused these letters patent to be executed.