The one circumstance connected with the career of Yvo de Vesci that has come down to us is the fact that he began to build the earliest parts of the existing castle of Alnwick. With the barony, the castle of Alnwick passed to Eustace Fitz-John by his marriage with Beatrix, the heiress of Yvo de Vesci. In the hands of this able baron, Alnwick Castle was “most strongly fortified:” he also founded the monastery of Alnwick, and in 1157 was succeeded by his eldest son, William, who, in honour of his mother, assumed the name of De Vesci. In the time of this baron, another King of Scotland found that the neighbourhood of Alnwick Castle was no place of safety. In the year 1174 William the Lion, while besieging the fortress of the De Vescis, was taken prisoner, and the large army under his command was completely routed, De Vesci himself taking an active part in the fierce struggle. His descendant, John De Vesci, who died in 1288, leaving no issue, founded and endowed Hulne Abbey; and he was the first baron of his house who was summoned by the king to the parliament by writ, his predecessors having been barons by tenure. William De Vesci III., one of the claimants of the Scottish crown, was born in 1245, and succeeded to the barony of Alnwick on the death of his brother. The last baron of Alnwick of his race, he died in 1297, without legitimate issue, having infeoffed the celebrated Anthony Bec, Bishop of Durham, with all his lands and his castle of Alnwick, to hold them in trust for an illegitimate son. But in 1309 the bishop sold the castle and barony of Alnwick to Henry de Percy; and this conveyance was confirmed by Edward II. in 1310. Deriving, as it would seem, their memorable name from that district in Normandy in which from an early period, long before the Norman Conquest of England, their family had been established, the PERCIES were represented in the ranks of the Conqueror at Hastings by William de Percy, who assumed the additional name of Le Gernons, or Algernon, as a personal epithet denoting the mass of hair which he wore about his face. About 1166, or almost an exact century after the battle of Hastings, the wealth, dignities, and power of the Percies centred in an heiress who, perhaps in 1168, married Josceline de Louvain, second son of the Duke of Brabant, and half-brother to the second queen of Henry I. of England. A legend has been preserved, which relates that on her marriage with Josceline, Agnes de Percy stipulated that her husband, at his own option, should assume either the arms or the name of Percy; and it is added that the bridegroom elected to retain his own arms, the blue lion rampant of Brabant, while he assumed the paternal surname of his bride. This legend, however, must be regarded as the poetic offspring of a later age, since at the time of the marriage of Agnes de Percy armorial insignia had neither assumed any definite character, nor had any such insignia become hereditary.