In February 1553, Edward VI became ill, and by June, after several improvements and relapses, he was in a hopeless condition.
The king's death and the succession of his Catholic half-sister Mary would jeopardise the English Reformation, and Edward's Council and officers had many reasons to fear it.
Edward himself opposed Mary's succession, not only on religious grounds but also on those of legitimacy and male inheritance, which also applied to Elizabeth.
He composed a draft document, headed "My devise for the succession", in which he undertook to change the succession, most probably inspired by his father Henry VIII's precedent.
He passed over the claims of his half-sisters and, at last, settled the Crown on his first cousin once removed, the 16-year-old Lady Jane Grey, who on 25 May 1553 had married Lord Guilford Dudley, a younger son of the Duke of Northumberland.
In the document he writes:
My devise for the Succession
1.
For lakke of issu [masle inserted above the line, but afterwards crossed out] of my body [to the issu (masle above the line) cumming of thissu femal, as i have after declared inserted, but crossed out].
To the L Franceses heires masles, [For lakke of erased] [if she have any inserted] such issu [befor my death inserted] to the L' Janes [and her inserted] heires masles, To the L Katerins heires masles, To the L Maries heires masles, To the heires masles of the daughters wich she shal haue hereafter.
Then to the L Margets heires masles.
For lakke of such issu, To th'eires masles of the L Janes daughters.
To th'eires masles of the L Katerins daughters, and so forth til yow come to the L Margets [daughters inserted] heires masles.

2.
If after my death theire masle be entred into 18 yere old, then he to have the hole rule and gouernauce therof.

3.
But if he be under 18, then his mother to be gouuernres til he entre 18 yere old, But to doe nothing w'out th'auise (and agremet inserted) of 6 parcel of a counsel to be pointed by my last will to the nombre of 20.

4.
If the mother die befor th'eire entre into 18 the realme to be gouuerned by the cousel Prouided that after he be 14 yere al great matters of importaunce be opened to him.

5.
If i died w'out issu, and there were none heire masle, then the L Fraunces to be (reget altered to) gouuernres.
For lakke of her, the her eldest daughters,4 and for lakke of them the L Marget to be gouuernres after as is aforsaid, til sume heire masle be borne, and then the mother of that child to be gouuernres.


6.
And if during the rule of the gouuernres ther die 4 of the counsel, then shal she by her letters cal an asseble of the counsel w'in on month folowing and chose 4 more, wherin she shal haue thre uoices.
But after her death the 16 shal chose emong themselfes til th'eire come to (18 erased) 14 yeare olde, and then he by ther aduice shal chose them" (1553).

— Edward VI, Devise for the Succession
In his document Edward provided, in case of "lack of issue of my body", for the succession of male heirs only, that is, Jane Grey's mother's male heirs, Jane's, or her sisters'.
As his death approached and possibly persuaded by Northumberland, he altered the wording so that Jane and her sisters themselves should be able to succeed.
Yet Edward conceded Jane's right only as an exception to male rule, demanded by reality, an example not to be followed if Jane or her sisters had only daughters.
In the final document both Mary and Elizabeth were excluded because of bastardy; since both had been declared bastards under Henry VIII and never made legitimate again, this reason could be advanced for both sisters.
The provisions to alter the succession directly contravened Henry VIII's Third Succession Act of 1543 and have been described as bizarre and illogical.

In early June, Edward personally supervised the drafting of a clean version of his devise by lawyers, to which he lent his signature "in six several places."
Then, on 15 June he summoned high ranking judges to his sickbed, commanding them on their allegiance "with sharp words and angry countenance" to prepare his devise as letters
In February 1553, Edward VI became ill, and by June, after several improvements and relapses, he was in a hopeless condition. The king's death and the succession of his Catholic half-sister Mary would jeopardise the English Reformation, and Edward's Council and officers had many reasons to fear it. Edward himself opposed Mary's succession, not only on religious grounds but also on those of legitimacy and male inheritance, which also applied to Elizabeth. He composed a draft document, headed "My devise for the succession", in which he undertook to change the succession, most probably inspired by his father Henry VIII's precedent. He passed over the claims of his half-sisters and, at last, settled the Crown on his first cousin once removed, the 16-year-old Lady Jane Grey, who on 25 May 1553 had married Lord Guilford Dudley, a younger son of the Duke of Northumberland. In the document he writes:
My devise for the Succession
1. For lakke of issu [masle inserted above the line, but afterwards crossed out] of my body [to the issu (masle above the line) cumming of thissu femal, as i have after declared inserted, but crossed out]. To the L Franceses heires masles, [For lakke of erased] [if she have any inserted] such issu [befor my death inserted] to the L' Janes [and her inserted] heires masles, To the L Katerins heires masles, To the L Maries heires masles, To the heires masles of the daughters wich she shal haue hereafter. Then to the L Margets heires masles. For lakke of such issu, To th'eires masles of the L Janes daughters. To th'eires masles of the L Katerins daughters, and so forth til yow come to the L Margets [daughters inserted] heires masles.
2. If after my death theire masle be entred into 18 yere old, then he to have the hole rule and gouernauce therof.
3. But if he be under 18, then his mother to be gouuernres til he entre 18 yere old, But to doe nothing w'out th'auise (and agremet inserted) of 6 parcel of a counsel to be pointed by my last will to the nombre of 20.
4. If the mother die befor th'eire entre into 18 the realme to be gouuerned by the cousel Prouided that after he be 14 yere al great matters of importaunce be opened to him.
5. If i died w'out issu, and there were none heire masle, then the L Fraunces to be (reget altered to) gouuernres. For lakke of her, the her eldest daughters,4 and for lakke of them the L Marget to be gouuernres after as is aforsaid, til sume heire masle be borne, and then the mother of that child to be gouuernres.

6. And if during the rule of the gouuernres ther die 4 of the counsel, then shal she by her letters cal an asseble of the counsel w'in on month folowing and chose 4 more, wherin she shal haue thre uoices. But after her death the 16 shal chose emong themselfes til th'eire come to (18 erased) 14 yeare olde, and then he by ther aduice shal chose them" (1553).
— Edward VI, Devise for the Succession
In his document Edward provided, in case of "lack of issue of my body", for the succession of male heirs only, that is, Jane Grey's mother's male heirs, Jane's, or her sisters'. As his death approached and possibly persuaded by Northumberland, he altered the wording so that Jane and her sisters themselves should be able to succeed. Yet Edward conceded Jane's right only as an exception to male rule, demanded by reality, an example not to be followed if Jane or her sisters had only daughters. In the final document both Mary and Elizabeth were excluded because of bastardy; since both had been declared bastards under Henry VIII and never made legitimate again, this reason could be advanced for both sisters. The provisions to alter the succession directly contravened Henry VIII's Third Succession Act of 1543 and have been described as bizarre and illogical.
In early June, Edward personally supervised the drafting of a clean version of his devise by lawyers, to which he lent his signature "in six several places." Then, on 15 June he summoned high ranking judges to his sickbed, commanding them on their allegiance "with sharp words and angry countenance" to prepare his devise as letters 
Edward VI of England