Off the Shelf: Mad, vain and thrice noble: Kenneth Baxter on Margaret, Duchess of Newcastle's spirited life of her husband

ON 18 March 1668 Pepys 'staid at home reading the history of my lord Newcastle, wrote by his wife, which shows her to be a mad, conceited, ridiculous woman and he an ass to suffer her to write so of him.' Her contemporary, Dorothy Osborne, believed 'the poor woman is a little distracted. Sure there are many soberer persons in Bedlam'. Yet Charles Lamb called her 'that princely woman, the thrice noble and virtuous but somewhat fantastical and original- minded Margaret Newcastle. No binding could be too fine for such a good and rare book, no casket rich enough to honour and keep safe such a jewel'.

It was one of many jewels: poems, orations, letters and philosophical discourses, which occupied her day and night when not devising extravagant clothes for herself and her servants. Her conduct was chaste, her language shockingly coarse. She desired 'fame above all', which she certainly enjoyed - crowds gawped at her equipage as she drove through the park. And she was insatiably vain, 'vanity being natural to our sex and unnatural not to be so'. One of eight brothers and sisters, she had no academic education, and needed none.

Fortunately, her husband shared her enthusiasms. He was himself a miscellaneous author and the patron of such men as Hobbes, Dryden, Jonson and Descartes. The Stuarts had no more loyal servant. He entertained Charles I and his Queen at Bolsover with spectacular magnificence and during the Civil War put himself and his fortune absolutely at the king's service. Though more scholar than soldier he fought valiantly until, discouraged by Prince Rupert's foolhardy conduct in battle, he retired to the Continent. On his return he found his estates ruined, patiently rebuilt them and lived quietly with his wife in the country.

Her Life of William Duke of Newcastle is a thorough job, divided into four books. Book I gives a valuable account of the campaigns in which 'my Lord' was engaged in the Midlands and North. Book II concerns his activities after he left the country to do what he could in exile for the royal cause. There, 'I being one of her Majesty's maids of honour, he was pleased to take some particular notice of me inasmuch that he resolved to choose me for his second wife'. He wanted heirs but 'God frustrated his designs by making me barren, which did never lessen his love for me'. Book III describes 'his person, natural humour, qualities, virtues, his loyalty and sufferings, prudence and wisdom, diet, exercises, etc'. Finally, in Book IV, we have his sayings, noted by her as they relished their post-Restoration seclusion at Welbeck. It is all entertaining stuff; and one wonders if, when Pepys read it after a day at the office, 'my eyes being very bad', he was feeling less than his tolerant self.