Memory of the World
Treaty of Tordesillas: originals, ratifications and access
Explore the 1494 Treaty of Tordesillas, registered in 2007, its ratifications held in Lisbon and Seville, and catalogue references for documentary research.
- Document dates
- 1494
- UNESCO
- Memory of the World · since 2007
The Treaty of Tordesillas, agreed on 7 June 1494, established a demarcation line between the crowns of Portugal and Castile, from pole to pole, 370 leagues west of the Cape Verde islands. UNESCO entered it on the Memory of the World Register in 2007, following a joint nomination by Portugal and Spain. Understanding this heritage means distinguishing the diplomatic agreement from the documents ratifying it.
One agreement, two ratifications
The Catholic Monarchs, Isabella I of Castile and Ferdinand II of Aragon, ratified the treaty at Arévalo on 2 July 1494. João II ratified it at Setúbal on 5 September. Searching for July or September dates can therefore identify ratification instruments of the June agreement, rather than different treaties.
The Castilian version is held at Torre do Tombo in Lisbon. The Portuguese version is held at the Archivo General de Indias in Seville. The instrument’s language and the crown validating it do not match its present country of custody.
Finding the right record
The Torre do Tombo record identifies the Castilian ratification as PT/TT/GAV/17/2/24, dated 2 July. Its description also mentions associated facsimiles and certificates. The files displayed do not automatically represent an equal number of originals from 1494.
In PARES, look for PATRONATO,1,N.6,R.1: the Portuguese ratification is described as an original, dated 5 September, bearing João II’s signature. The neighbouring record PATRONATO,1,N.6,R.2 describes a copy made in 1524, although its creation field shows 1494. Reading the scope and content prevents confusion between a copy and the inscribed original.
Reading the demarcation line
The agreement helps explain the two crowns’ territorial claims and diplomacy, and the subsequent framework for Portuguese presence in Brazil. The formula of 370 leagues should not, without further study, be converted into a modern boundary of known precision.
Read the document as an expression of the powers negotiating the division. Heritage registration does not make their claims evidence of consent by the peoples of the territories concerned. Compare the diplomatic text with other sources on the consequences of expansion.
Preparing your research
Save the archive, reference, language, ratification date and link for each version. Check available images and confirm reproduction and original-access conditions with each institution. Archival custody does not guarantee permanent public display.
For other evidence from the period, explore the Corpo Cronológico and the Letter of Pero Vaz de Caminha. They are separate documentary inscriptions with different units and production contexts.
Frequently asked questions
- When was the treaty agreed and ratified?
- The agreement was concluded at Tordesillas on 7 June 1494. The Catholic Monarchs ratified it at Arévalo on 2 July; João II ratified it at Setúbal on 5 September. The agreement date differs from those of its ratifications.
- Which version is held in Lisbon?
- Torre do Tombo holds the Castilian ratification, PT/TT/GAV/17/2/24. João II’s Portuguese ratification is held at the Archivo General de Indias in Seville, under PATRONATO,1,N.6,R.1.
- What does UNESCO registration recognise?
- Portugal and Spain jointly registered the documentary heritage on the international Memory of the World Register in 2007. This does not inscribe the town of Tordesillas or the archive buildings on the World Heritage List.