I became used to seeing the Duke: at a distance, at close quarters in the midst of his family, but in public always with that careful separation between us. There must be no suspicion, no careless moment of intimacy to cause an in-drawing of breath from a casual observer. No indiscreet comment that presumed knowledge that should not exist. How it kept me on my toes, to dance to this complicated tune. And I learned to tolerate that void between us, knowing that it would be bridged when he could. His awareness of me was a tangible thing, but handled with delicacy.

The pattern of my days was laid down when we went hawking in the marshes across the river: a family party on horseback, a noisy collection of children with servants to accompany and safeguard. Constanza too, who relished the exercise, and her damsels.

He was frequently with Constanza in those days.

Sister Philippa rode at my side as I kept an eye on Elizabeth who was headstrong. Henry and my son Thomas had their heads together in some plotting. Perhaps one day, I thought absently but with no real hope, my son John would participate in such an outing as this with his father. For there in the midst was the Duke, a keen owner of a new pair of goshawks.

We flew them at pigeons and wading water-birds.

When the Duke handed a little merlin to me, our gloved hands touched as they must. How was it possible to experience the heat of another’s hand through two layers of stitched leather of the hawking gloves?

Neither of us exhibited any acknowledgement.

But afterwards, when the falconer returned the hawks to their perches, and the children were engaged in their afternoon occupations, when Constanza knelt at her prie-dieu to petition God for a son and Philippa cared for Katalina, he came to me in my chamber and all my yearnings were fulfilled. When he possessed me, I was a willing captive.

The rumours began, as they must. Did we think we could exist on our gilded cloud of secrecy for ever? Only a fool would give any weight to the possibility.

What was it that drew attention?

I knew not.

First the whispering started, the sibilance of words cut off, or almost smothered, when I entered the room. Constanza’s damsels, like their mistress, had a better command of French now, and their vocabulary was not always that of gently reared women. Even when the consonants were hissed in pure Castilian, their meaning was clear. A minor inconvenience, I told myself. I was no naïve girl to believe that so physical an affair could remain a secret in the hotbed of the Duchess’s household where gossip was the order of the day. They dared not be overtly discourteous, and they were careful not to express their opinions in the Duchess’s company.

The observations were predictable, I supposed.

Who was ever to know the source of such rumours? What I did know was that it would only be a matter of time before the torrid Castilian details came to Constanza’s ear. And then, would she insist on my dismissal to rid herself of my contaminating presence?

It worried me enough for me to consider: what would the Duke do if caught in a direct line of conflict between wife and mistress? As a man of honour, of known chivalry, he could hardly support his mistress before his royal wife. As a man of ambition, he could not ignore the wishes of a wife who could bring him the crown of Castile for his own.

I set my teeth and applied myself to the raising of my lover’s children, trying not to allow my thoughts to linger with my own small son so far away. I had made my bed. Now I must lie in it, with all the confidence and composure I could muster. When the vile accusations reached me, I raised my chin and pretended that I was invulnerable.

But I could not lay claim to a thickness of skin for long. A constant irritant must soon cause an abrasion, like a stone in the heel of a shoe, and the abrasion showed signs of becoming an open wound when my sister heard the rumbling undercurrent from her solar companions. Nor was that the worst of it. For when our paths crossed, as they must in one of our sojourns at The Savoy, there deep in conversation with Philippa was a figure I could not mistake, and who I wished in that moment of recognition far from England’s shores.

Short and stout, son of a London Vintner and so not of Philippa’s social worth—which always rankled with her—Geoffrey Chaucer was the other half of her arranged marriage and a man of many things. Most dangerously, a man of clever mind and wicked pen. A shame, I thought, as I approached them, that he didn’t love my sister as much as he loved his books. They were clearly, audibly arguing. I considered walking smartly past, but then slowed my steps. Argument was a frequent occurrence in that marriage and I was not without sympathy for Philippa. I might rescue her.

‘Where are you going?’ my sister demanded of him.

‘You know better than to ask.’ Geoffrey grinned. The world of cynical patience on his lips would have driven a better woman to harsh words.

‘So when will you be back? Can you tell me that?’

‘When the royal business is done.’

A writer of naughty verses but a sublime wit, a composer of poetry, of songs and ballads under the generous patronage of the Duke, Geoffrey looked ripe for escape.

Hearing me approach, he looked over his shoulder. ‘Katherine…’

Our eyes were not quite on a level, and so he had perforce to stretch to kiss my cheek, while his eyes gleamed, sharp as a hunting knife, with some unspoken idea that I thought I might not like.

‘Geoffrey,’ I replied. I was always careful around him, what I said and did not say. Every mild, insubstantial implication could be caught up like a pike snapping up a summer mayfly in its maw for he had an unrivalled way with words. ‘So you are telling us nothing?’

‘As usual,’ Philippa said, unable to risk rising to the bait.

‘Out and about on the King’s secret affairs?’ I suggested with a smile.

As well as a man of letters, Geoffrey was also a military man. A courier. A spy, some said. I could well believe it.

‘Of course.’ He made a neat little bow. ‘It is my employment. Even if my wife still takes exception to it.’

‘I take exception because I am not considered important enough to know of your business dealings,’ his wife retaliated.

‘What you don’t know you can’t gossip about. Do you lack for anything?’

‘Nothing that you are willing to give me!’

I sighed quietly. How they ever had children together when they spent so little time in each other’s company and with so little charity between them I could not guess. Then Geoffrey’s eyes slid to fix on mine. Bright as an acquisitive magpie locating something desirable.

‘And what of you, Katherine? I’m hearing astonishing things about you.’

‘Now what could they be?’ My insouciance was marvellous considering the sudden beat of my heart. I had no wish to be portrayed in any manner, good or bad, by his greedy pen.

‘I’ll not say…Or not yet. I’ll consider it. Now I’m off.’

He saluted my cheek again, whispering, ‘There are many who will say. Watch your step, Lady de Swynford.’ He landed a brief peck on Philippa’s cheek and strolled out.

I would have followed.

‘Is it true?’

Philippa thrust out a hand to stop me, her brows climbing to her plucked hairline, mine tightening into a straight line that could quickly become a frown. I had anticipated this confrontation almost as much as I feared the one with Constanza.

‘Is what true?’ I withdrew my sleeve from her clasp, praying that she had not uttered one word of her suspicions to her husband. Who knew where he might turn his agile mind next? Geoffrey, fervent admirer of Duchess Blanche that he was, had been pleased to portray the Duke as the grieving widower in his Book of the Duchess. He might equally well turn him into a pariah if he caught any whiff of scandal.

‘Whore? Harlot? Is it true?’

And here was Philippa, selecting the most common of the words, as she worked out her fury with Geoffrey on me. My earlier compassion drained fast away.

‘Yes.’ What use in denying it? The words still echoed in my head from the breaking of our fast, murmured over the ale and bread so that I would hear. ‘Although I would not have put it in quite those terms.’

The damsels had, more fluently. Puta. Hija de Puta. Mujerzuela. Even in their own tongue, the meaning was ugly. Whore. Slut. Harlot.

‘And when were you going to tell me?’ Philippa demanded, hard-eyed. ‘Or is your sister no longer in your confidence?’

‘I’m sorry. I should have told you.’ I would apologise for a sin of omission but nothing else. I held her stare as we stepped aside when a maid from the dairy came between us bearing a round of cheese. Philippa picked up her weapons as soon as the cheese was gone.

‘You should be ashamed of yourself. But I don’t suppose you are, or you would not be back here. You would be holed up at Kettlethorpe.’

I stiffened. I took up the challenge immediately.

‘No. I am not ashamed. I love him, and I’ll not ask your permission, your approval or your forgiveness. It is not your affair, Philippa.’ Yes, it was a curt reply but I could see from her face that there would be no understanding from her. ‘Now, if you will let me pass…’ The damsels’ words had ruffled me more than I had cared to admit.

Philippa stepped again to bar my way.

‘And I suppose you do have a son, as the Castilian bitches say?’ she murmured. At least she kept her voice down. ‘Would you not have found the opportunity to tell me that either? That I have a bastard nephew by the Duke of Lancaster?’

No, I had never told her. I had told no one. And as I sensed a gloss of hurt running over her accusations, I felt a little flicker of regret that my sister should have discovered the truth from cruel gossip. Why had I not told her? Because I did not want to hear those crude words on the lips of my own sister.

‘Yes. I do have a son,’ I replied, keeping my voice quiet in the confined space as unlooked for emotion struck at me. ‘He is called John. He is almost three months old, and bears too much resemblance to the Duke for me to bring him with me. I love him with all my heart. And I miss him.’

Philippa was unmoved. ‘And you are a hypocrite, sister Kate. You are here under false pretenses. In her household—or as near as—and she does not know. I pity her, and I condemn you for your cruelty.’

This is what I had dreaded. Philippa’s marriage to Geoffrey Chaucer had brought her no joy and had hardened her spirit.

‘Oh, Philippa!’ Suddenly overwhelmed with remorse for her loveless state, I touched her arm. ‘I am sorry for your own squabbles with Geoffrey, but what I do or do not do has no bearing on it. Nor did I steal the Duke’s love from Constanza.’

‘You don’t know that! Is that what he tells you?’

‘Yes, he does.’

‘Well, he would, wouldn’t he?’

‘He would not lie to me, I know that. Their marriage was one of political expediency, as she would be the first to admit. I cannot bear guilt for her dissatisfaction, just as I cannot live my life to please you. I am not responsible for the lack of satisfaction in your own marriage.’

Philippa visibly flinched as if I had struck her cheek. We never talked of her unhappiness.

‘I do not expect you to live your life to please me.’

‘Yet you think I should repudiate the man I love.’

‘Yes, I do, when we all live cheek by jowl…’

‘Would you?’ I asked.

‘Would I what?’

‘If you loved your husband so much that he occupies your every thought, would you not follow him to the ends of the earth?’ She flushed. ‘I know there is little between you. But if there were…’

‘We are not talking about me.’

‘No. You are picking apart my emotions, my morals. My private life.’

‘You have no private life.’

‘But you do not have the right to hang it out to dry for the damsels to gloat over.’

It silenced her.

‘All I ask is that you do not add your own voice to the gossip. And,’ I added, trying a smile, ‘that you do not entertain Geoffrey with the details. I don’t wish to be pilloried in some fashionable song. Will you do that for me?’

‘Oh, I’ll not talk about it to anyone,’ Philippa responded, rejecting my olive branch. ‘I am not proud of what my sister is doing, even if she claims to be lost in love. Is that why you received such an astonishing annuity from the Duke? For your offices in his bed?’

‘And if it was?’ I was severely discomfited, horrified that she should think that.

‘Shame on you, Kate. If it matters to you at all, Constanza is unaware.’ Her lips sneered, something I had never seen before. ‘I don’t suppose you care. You will brazen it out, flaunting your pre-eminence.’