The history of Mogadouro is evident in the number of castros that dot the landscape of region from the neolithic period. In particular are the castros of Oleiros in Bemposta, Vilarinho, São Martinho do Peso, Figueirinha de Travanca, Bruçó and the more recently excavated castro in Vilariça, in the Serra da Castanheira.
The Celts passed through this region, leaving behind its art and religion, the so-called Cultura aos Berrões. One of these Celtic tribes, the Zoelae, were responsible for settling many of the lands along the Douro, Sabor and Angueira Rivers.
During the Roman period, the region is referred to in art, religion and socio-economic reports, indicating its regional importance.The Ara Romana to Deus Jupiter Depulsori (which still survives to this day in Saldanha), is one of these remnants of this period (it was constructed during the reign of Septimius Severus in the 3rd century BC). Throughout the municipality that are have been discovered many funerary stones and artefacts that attest the Romanization of these lands.
Vestiges of the Visigothic era are rare, but include a paleo-Christian inscription that was discovered in São Martinho do Peso (now in the Abade de Baçal Museum in Bragança.
Moorish influence in this region is limited to local handicrafts made from flax and wool, that includes the hand embroidery, quilts, rugs and towels. During the Reconquista era, it is known that Alfonso III of León effected many construction projects during his reign, that were more strategic then political: organizing a military line along the Douro with castles (to protect the holdings of the León while inducing incursions into Moorish lands, populating conquered territory and taking advantage of natural geography to defend his territory. After fortifying Zamora, around 893, he ordered the construction of castles along the line, repopulating them as he progressed. Toro and Simancasdeveloped consequently from this policy. It is likely that the area of Mogadouro was settled as a strategic point along the line, resulting in the construction of the first fort. The regions name evolved from this settlement: Mógo means a implanted marker, considered a symbolic delineation of the separation or division of a territory, a term imported from common language at the time. The mógo do Douro (mark on the Douro), or Mogadouro, developed from this locational designation.
The Castle of Penas Róias was constructed during the nation-building of Afonso Henriques. The stone of the cell-block tower is inscribed with a medieval statement:“Começaram os fundamentos do Castelo chamadao Pena Roia na era de 1204 sendo Mestre Geral dos Templários Gualdim Pais” [They began the fundamentals of the Castle Pena Roia in the era of 1204 by Master General of the Templar Gualdim Pais]. The later Castle of Modagouro, from the same decade, was started prior to the establishment of the civic charter (foral) in 1272/73. During the Portuguese dynastic crisis (or Interregnum) the noble classes supported the King of Castile, resulting in an eventual reprisal by Prince John (who elevated the hamlet of Azinhoso and parsed it from Mogadouro). Consequently, although its economic activity did not contract, the lack of royal patronage meant that Mogadouro remained stagnated until the 16th century.
Mogadouro, historically, fell within the Caminhos de Santiago, a capillary of secondary roadways that extended throughout the Trás-os-Montes region leading pilgrims down Saint James Way. The principal road arrived in Mogadouro from Castelo Rodrigo, from two routes: from Freixo de Espada à Cinta (Castelo Rodrigo, Figueira de Castelo Rodrigo, Escalhão, crossing the Douro by boat in Barca de Alva, Quinta de Santiago, Freixo de Espada à Cinta, Mós, Fornos, Lagoaça, Bruçó, Mogadouro); the other from Moncorvo (Castelo Rodrigo, Figueira de Castelo Rodrigo, Almendra, Castelo Melhor, Vila Nova de Foz Côa, crossing the Douro by boat in Pocinho, Moncorvo, Vilariça, Adeganha, Parada, here crossing the Sabor in Santo Antão da Barca before reaching Mogadouro). The Caminho de Santiago forked in Mogadouro at the Chapel of Nossa Senhora do Caminho (Caminho de Santigao): to Azinhoso (a enormous enclosure existed near the Church of Azinhoso to provide shelter during the crossing), then over a medieval bridge that connected Penas Roias, Algoso, Vimioso to Bragança; the other road departed from the Church of Nossa Senhora do Caminho, to Santiago, then Algosinho (to another pilgrimage church), Ventoselo (where there still remains vestiges of the pilgrimages, such as the roof painting in the Chapel of Nossa Senhor da Boa Morte), on the way passing by a spring (where pilgrimages would satisfy their thurst), to another chapel to Santigao (now completely destroyed), Urrós, Sendim, and Miranda do Douro). There were several tributaries, shortcuts and dirt tracks on the pilgrim roadways, such as: through Azinhoso (where the faithful would rest in the chapel to São Gonçalo, a patron saint of the travellers); through Variz, Castanheira, Valcerto, Algoso, Campo de Víboras and Vimioso; through Santiago (now Vila de Ala), an important crossroads between Peredo de Bemposta (through Algosinho, Ventoselo and Vila de Ala) and Bemposta (through Lamoso, Tó and Vila de Ala). Those who travelled from the southern part of the district would likely stop in Zava (where a chapel to São Cristóvão, the saint protector, was located).
It was after the 16th century that Mogadouro saw some growth. The Távora family, a noble house with influence and power in court, controlled the region, commanding the fort and guiding the town, generally contributing to the development of the lands within their domain. It was through the action of the Távoras that the local Santa Casa da Misericórdia was founded in 1559, and its local church. The bridges between Valverde and Meirinhos (in 1677), and the Remondes bridge, between Mogadouro and Macedo de Cavaleiros (in 1678) were also constructed with the patronage of the Távoras. In addition, the family supported the constructions of a few churches and altars in various municipalities throughout the 17th–18th century, including the Convent of São Francisco, the Matriz Church of Mogadouro, the Chapel of Nossa Senhora da Ascensão, in the heights of Serra da Castanheira and many others. But, by act of King Joseph I the Távoras lands were confiscated by the Marquess of Pombal, and members of the family executed after anattempted-assassination of the monarch. The annilhation of the family resulted in the loss of development impetus.
The municipal archive, installed in the Convent of São Francisco (today the Mogadouro Municipal Chamber) burned down in 1881 (and again later in 1927).
After the extinction of the monastic orders, by the Liberal government, the Convent of São Francisco was appropriated to store public records and local administration.
By the 19th century, few of the noble families were interested in their holdings in Mogadouro, nor did they do much to develop these lands. By the end of the 20th century, only the poet-jurist José Francisco Trindade Coelho defended his land rights, and the region was abandoned by the central hierarchy of Lisbon.
The Sabor line, a narrow gauge railway, served the community between 1930 and 1988.