Returning from war, he became once more the student, presenting in 1632 the library he had purchased of his friend Allen, to the Bodleian Library, and devoting his powers to the mastery of controversial divinity. Having in 1636 entered the Church of Rome, he resided for some time abroad. Amongst his works at this period were his "Conference with a Lady about the Choice of Religion," published in 1638, and his "Letters between Lord George Digby and Sir Kenelm Digby, Knt., concerning Religion," not published till 1651. It is difficult to say to which he was most devoted--his King, his Church, literature, or his beautiful and frail wife, Venetia Stanley, whose charms fascinated the many admirers on whom she distributed her favours, and gained her Sir Kenelm for a husband when she was the discarded mistress of Richard, Earl of Dorset. She had borne the Earl children, so his Lordship on parting settled on her an annuity of £500 per annum. After her marriage, this annuity not being punctually paid, Sir Kenelm sued the Earl for it. Well might Mr. Lodge say, "By the frailties of that lady much of the noblest blood of England was dishonoured, for she was the daughter of Sir Edward Stanley, Knight of the Bath, grandson of the great Edward, Earl of Derby, by Lucy, daughter and co-heir of Thomas Percy, Earl of Northumberland." Such was her unfair fame. "The _fair fame_ left to Posterity of that Truly Noble Lady, the Lady Venetia Digby, late wife of Sir Kenelm Digby, Knight, a Gentleman Absolute in all Numbers," is embalmed in the clear verses of Jonson. Like Helen, she is preserved to us by the sacred poet. "Draw first a cloud, all save her neck, And out of that make day to break; Till like her face it do appear, And men may think all light rose there." In other and more passionate terms Sir Kenelm painted the same charms in his "Private Memoirs." But if Sir Kenelm was a chivalric husband, he was not a less loyal subject. How he avenged in France the honour of his King, on the body of a French nobleman, may be learnt in a curious tract, "Sir Kenelme Digby's Honour Maintained. By a most courageous combat which he fought with Lord Mount le Ros, who by base and slanderous words reviled our King. Also the true relation how he went to the King of France, who kindly intreated him, and sent two hundred men to guard him so far as Flanders. And now he is returned from Banishment, and to his eternall honour lives in England."