Ferdinand II and Joanna met at Hornillos, Castile on 30 July 1507.
Ferdinand then constrained her to yield her power over the Kingdom of Castile and León to himself.
On 17 August 1507, three members of the royal council were summoned - supposedly in her name - and ordered to inform the grandees of her father Ferdinand II's return to power: "That they should go to receive his highness and serve him as they would her person and more."
However, she made it evident that this was against her will, by refusing to sign the instructions and issuing a statement that as queen regnant she did not endorse the surrender of her own royal powers.

Nonetheless, she was thereafter queen in name only, and all documents, though issued in her name, were signed with Ferdinand's signature, "I the King".
He was named administrator of the kingdom by the Cortes of Castile in 1510, and entrusted the government mainly to Archbishop Cisneros.
He had Joanna confined in the Royal Palace in Tordesillas, near Valladolid in Castile, in February 1509 after having dismissed all of her faithful servants and having appointed a small retinue accountable to him alone.
At this time, some accounts claim that she was insane or "mad", and that she took her husband's corpse with her to Tordesillas to keep it close to her.
Ferdinand II and Joanna met at Hornillos, Castile on 30 July 1507. Ferdinand then constrained her to yield her power over the Kingdom of Castile and León to himself. On 17 August 1507, three members of the royal council were summoned - supposedly in her name - and ordered to inform the grandees of her father Ferdinand II's return to power: "That they should go to receive his highness and serve him as they would her person and more." However, she made it evident that this was against her will, by refusing to sign the instructions and issuing a statement that as queen regnant she did not endorse the surrender of her own royal powers.
Nonetheless, she was thereafter queen in name only, and all documents, though issued in her name, were signed with Ferdinand's signature, "I the King". He was named administrator of the kingdom by the Cortes of Castile in 1510, and entrusted the government mainly to Archbishop Cisneros. He had Joanna confined in the Royal Palace in Tordesillas, near Valladolid in Castile, in February 1509 after having dismissed all of her faithful servants and having appointed a small retinue accountable to him alone. At this time, some accounts claim that she was insane or "mad", and that she took her husband's corpse with her to Tordesillas to keep it close to her.
Joanna of Castile