Nicholas de Segrave, who in 43rd of Henry III attended that monarch into France, but soon after espoused the cause of the Barons, and became one of their most active leaders. In 47th of Henry III, 1263, he was amongst those who appeared openly in arms and fortified Northampton, for which reason his lands were seized by the crown. Upon the subsequent fall of Northampton to the royalists, Nicholas fled to London, where the citizens, having raised a large army for the barons, made him their General. At the head of this force, he marched with Gilbert de Clare and Henry de Hastings to Rochester, and thence to Lewes, at which place the celebrated battle so disastrous to the King commenced, by a charge made by Segrave at the head of the Londoners; in this he was worsted by Prince Edward, who, flushed with success, pursued his advantage too far and thus mainly contributed to the defeat which the royal cause sustained. The King, Edward and their chief adherents became prisoners to the rebels, who followed up their triumph by immediately summoning a Parliament in the King's name, to which Nicholas Segrave was summoned as Baron Segrave Dec. 25, 1264. But, the tide soon ebbing, he was among the defeated at Evesham, where he was wounded and made prisoner. He received full pardon and in four years attended Prince Edward to the Holy Land, and when that Prince ascended the throne as Edward I, he appears to have enjoyed a large share of royal favour. He was later in the Scottish and Welsh wars and had a second summons to Parliament June 24, 1295. He married Maud de Lucy, and had John, Nicholas, Geoffrey, Peter, Gilbert, Annabel and Eleanor.