| Teodósio I | |
| Succession: | Duke of Braganza |
| Reign: | 20 September 1532 – |
| Reign-Type: | Tenure |
| Predecessor: | Jaime I |
| Successor: | João I |
| Spouse: | Isabel of Lencastre Beatriz of Lencastre |
| Issue: | João I, Duke of Braganza |
| Issue-Link: |
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| Issue-Pipe: | among others... |
| House: | House of Braganza |
| Father: | Jaime I, Duke of Braganza |
| Mother: | Leonor Pérez de Guzmán |
| Birth Date: | 1510 |
| Birth Place: | Vila Viçosa, Alentejo, Kingdom of Portugal |
| Death Date: | 22 September 1563 |
| Death Place: | Vila Viçosa, Alentejo, Kingdom of Portugal |
Dom Teodósio I of Braganza (Portuguese: Teodósio de Bragança; 1510 – 22 September 1563) was the 5th Duke of Braganza, among other titles. He is known for ceding the title of Duke of Guimarães to Infante Duarte of Aviz, alongside some of the wealth and properties of the House of Braganza.
The Duke Teodósio I was an educated and refined man, a typical Renaissance prince. He loved painting and sculpture.
In 1542, he married his 1st cousin Isabel of Lencastre (1513–1558), daughter of his uncle Dinis, and had John (João) I of Braganza, who succeeded him as 6th Duke of Braganza.
In 1559, he remarried with Beatriz of Lencastre (1542–1623), granddaughter of Infante George of Lencastre, Duke of Coimbra. Their first child, Jaime of Braganza, died without issue in 1578, in the Battle of Alcacer Quibir. Their second child, Isabel, married the 1st Duke of Caminha.
| Name | Birth | Death | Notes | |
|---|---|---|---|---|
| João I | 1543 | 22 February 1583 | 13th Count of Barcelos, 10th Count of Ourém, 7th Count of Arraiolos and Neiva, 6th Duke of Braganza, 5th Marquis of Vila Viçosa | |
| Jaime | unknown | 4 August 1578 | Died at the Battle of Alcacer Quibir; never married; no issue | |
| Isabel | 1560 | unknown | Married Miguel Luis de Meneses, 1st Duke of Caminha |
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