On 25 Apr 1457 John Neville 1st Marquess Montagu (age 26) and Isabel Ingaldsthorpe (age 16) were married by Cardinal Thomas Bourchier (age 39) at Canterbury Cathedral [Map]. She the heir of her father Edmund Ingaldsthorpe who had died the previous year. Eight manors were settled on them in jointure. He the son of Richard Neville Earl Salisbury (age 57) and Alice Montagu 5th Countess of Salisbury (age 50). They were second cousin once removed. He a great x 2 grandson of King Edward III of England. She a great x 5 granddaughter of King Edward "Longshanks" I of England.

In 1460 a petition noted "The Nevilles state that Isabel was found to be Ingoldisthorpe's daughter and heir. When they requested livery of the estates from the chancellor in Chancery, he refused on the grounds that the king had granted the marriage and wardship to the queen (age 27). The Nevilles disputed this as Isabel was 14, and not a minor at common law. John Neville (age 26) made recognizances in £1,000 to the queen on the understanding that if it was found that such a grant to the queen was not available, then she would not take any money from Neville. The Nevilles are unable to have a day in their law, and the queen has still levied part of the £1,000, and they are forced to sue a special livery at great expense. They request that the recognizances by annulled, and that women of the age of 14 when their ancestors die should have no problem of obtaining livery of their lands and tenements." See National Archives UK John Nevyll (Neville), knight; Isabel Neville, wife of John Neville, knight. SC 8/28/1398 1460.