Even the gentle Queen Katherine wrote and sorrowfully reminded my mother that she had committed the great sin of disparaging my legitimacy. Mother wrote back tersely that she had married Father in good faith, so that could not be in question.

But Father had no time for legal niceties. I was nearly twelve when he came to our house in Edinburgh one day and demanded that I leave with him immediately.

‘Your mother is not fit to have custody of you,’ he grimaced.

Mother flew at him. ‘And you are, rutting with your mistress as you do?’

He would not deign to answer that. He waited while my nurse packed my gear and put on my warm cloak. Mother was shrieking and swearing, but he heeded her not, and I shrank into a corner, just wanting it to end. I was not averse to going to live with Father. I was tired of Mother’s tirades and her complaints about us being poor. I knew I would have a better life with Father. He, at least, was cheerful company.

‘As your father and a peer of the realm, I have every right to have custody of you, child,’ he said, as we rode up to Edinburgh Castle. ‘Regrettably, your mother is a bad moral influence.’

I was too young to have to confront moral issues. It was hard for me to have to choose between my parents. I did miss Mother, more than I had expected, but I was even more upset that she made little effort to get me back. But, after witnessing one too many scenes between her and Father, I was grateful to be able to lead a more stable life – for a time, at least.

Father sent me to live at Tantallon Castle, his magnificent and forbidding fortress of red stone, spectacularly situated high on a rocky headland overlooking the sea. It was a Douglas stronghold, of course, built to withstand attacks by armies. Father placed me there to prevent Mother and her supporters spiriting me away. The sea was on one side, the ramparts and a huge ditch on the other. It was impregnable.