A licence to crenellate
(furnish with battlements) was granted in 1266.
Since the license to crenellate
was granted in 1382, this strongly suggests that the portcullis is original (the wood is too weak to allow samples to be taken for dendrochronological analysis).
In 1434, King Henry V granted a licence to crenellate
a wall around Alnwick, which took over fifty years to complete.
There was a previous house on the same site, dismantled in the Civil War, and before than, a medieval, fortified house, awarded a licence to crenellate
It was the medieval home of the Muschamp family and in 1341 a licence to crenellate
(to fortify a building) was granted to Thomas de Muschamp, In 1415 a tower was recorded and in 1801 work began on the present castle-style mansion.