The Treaty of Newcastle was a treaty signed between King Henry III of England

Henry III of England

Henry III was the son and successor of John as King of England, reigning for 56 years from 1216 until his death. His contemporaries knew him as Henry of Winchester. He was the first child king in England since the reign of Æthelred the Unready...

 and King Alexander II of Scotland

Alexander II of Scotland

Alexander II was King of Scots from1214 to his death.-Early life:...

 on 14 August 1244.

The armies of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 and Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 were enroute to enagage in combat after disputes concerning the exact position of the border could not be resolved. After the two opposing armies met near Newcastle Upon Tyne

Newcastle upon Tyne

Newcastle upon Tyne is a city and metropolitan borough of Tyne and Wear, in North East England. Historically a part of Northumberland, it is situated on the north bank of the River Tyne...

 the hostilities were cast aside and a treaty signed which set the border between Scotland and England.

The treaty was sealed by the arrangement of the future marriage of Henry III’s daughter, Margaret

Margaret of England

Margaret of England was a medieval English princess who became Queen of Scots. A daughter of the Plantagenet king Henry III of England and his queen, Eleanor of Provence, she was Queen consort to Alexander III "the Glorious", King of the Scots.- Family :She was the second child of Henry III of...

 to Alexander II’s son, Alexander

Alexander III of Scotland

Alexander III was King of Scots from 1249 to his death.-Life:...

.