The only one of six brothers not to be educated at Cambridge or the Middle Temple, Montagu had the manor of Hanging Houghton ‘liberally bestowed on him’ by his father, Sir Edward†, who presumably also arranged his marriage with Anne Morgan, whose wardship had been purchased by Sir William Herbert† of St. Julian’s. Montagu’s wife was heiress to the Monmouthshire estate of her uncle Sir William Morgan, variously reckoned to be worth £200-£1,000 a year, which had been extended by the Crown for a debt of 2,000 marks but was leased back to the family. Sir Edward Montagu took over this lease in November 1588, but the marriage was deferred for 15 months, until the bride was nearly 14.
Sir Walter appears to have followed the family tradition of vigorously exploiting his estates. In 1591, shortly after taking over his wife’s lands, he was prosecuted by the rector of Llanmartin, Monmouthshire over tithes payable on his demesne, and in 1605-7 he disputed ownership of the tithes of Houghton with his Northamptonshire neighbour, John Isham, who eventually leased them to him.
Although Montagu managed Houghton and his wife’s lands from the time of his marriage, he only held a reversion of these estates until his father’s death in 1602, following which he began to play a significant part in local affairs. His eldest brother, Sir Edward Montagu*, could probably have obtained a burgess-ship for him at Brackley or Higham Ferrers in 1604, but he is not known to have shown any interest in a parliamentary seat until 1614, when he secured the senior knighthood for Monmouthshire in the absence of a candidate from Raglan Castle. He left little trace in the surviving records of the session, being named to committees for the expiring statutes’ continuance bill (8 Apr.) and the bill to allow Sir Robert Wroth II* to sell lands to pay his debts (25 May) - the latter’s wife was his second cousin.
Montagu had clearly abandoned any hope of an heir as early as 1604, when he assigned a reversion of the manor of Houghton to his brother Sir Henry.
Montagu’s death on 23 Mar. 1616 came as a shock to his brother Sidney, who morbidly remarked that ‘he hath broken the ice to us, and we must follow after’.
Montagu’s wife remarried a distant relative, Sir John Morgan of Chilworth, Surrey, but she kept control of her goods and estates by assigning them in trust to Sir Henry and Sir Charles Mountagu, Arnold Oldisworth* and Sir Edmund Morgan*.
