ESTRADA = ROAD IN PORTUGUESE. However, the name is Spanish, not Portuguese. A bit confusing to start with, but a fact. This is not surprising, as Spain had many dialects and the North-Central and North-Western part of the Iberian Peninsula had strong Portuguese and Celtic influence.
The information on the origins of the surname ESTRADA come from two main sources: The Heraldic and Genealogical Enciclopaedia by the brothers García Carraffa and the Spanish Nobiliary by Julio de Atienza.
In this Web page you will find basic information about the surname.
The Surname Dictionay of the Heraldic and Genealogical Encyclopaedia has this to say about the origin of the ESTRADA lineage:
"...It had its primitive and very ancient parcel in the place of Estrada, that is part of the Ayuntamiento (municipality) of Val de San Vicente and the Judicial District of San Vicente de la Barquera, that today belongs to the province of Santander, but that in antiquity was included in the Asturias of Santillana, that comprised part of the provinces of Oviedo and Santander. On top of a rock, you can still see in the said place an ancient tower, and in it a shield with an eagle, which is the coat of arms of Estrada..." (Actually, the shield in the tower is not the pure and primitive one of Estrada, but that of the alliance with the Duque family <see below>, of which the Estrada shield is a part).
It is believed that he lineage originated at the parcel of land known as Estrada, in the last third of the First Millenium of our era and slowly evolved. They acquired power and received the first recognition, that of a coat of arms, in the 12th. Century.
The shield which is mentioned is on the left side of the tower.
Heraldic motto of the Estrada lineage:
"I am from the house of Estrada
founded on this promontory
I am older than Velasco
and to the king I owe nothing."
The Coat of Arms
According to the Heraldic and Genealogical Enciclopaedia, the primitive and pure coat of arms of the lineage was: In a field of gold, an eagle crowned by sable. This coat of arms was granted, in 1188, to Gonzalo Fernández de Estrada by the Emperor Frederick of Germany, after being present at the marriage ceremonies of Conrad, Frederick's son, with doña Berenguela, daughter of King Alonso VIII of Castille. Because of this coat of arms, some people believed the surname had a German origin, but this is not true.
An interesting observation is that the shield has French or Portuguese shape, which is unexplained.
The Estrada lineage from Asturias used this: Of silver, with a rampant lion of its color and a frame of red, with four gold asps and four castles of the same metal, alternatelly.
Source:Heraldic and Genealogical Enciclopaedia - Shield 570
Francisco de Estrada, neighbor of the city of Mexico, received from Emperor Charles V of Spain the following coat of arms: In a field of azure, a stone bridge of two spans over waves of azure and silver water, topped by a golden tower, lightened with azure. Frame of red, with seven pilgrim shells of silver, in its right half, and frame of silver with seven black ermine, in the left half.
Source: Heraldic and Genealogical Enciclopaedia - Shield 571
REALTIONSHIP TO THE DUQUE SURNAME.
A branch of Estrada that owned the parcel of land called Estrada linked to a branch of the Duque surname and the descendants thereafter used the composed surname Duque de Estrada. The place of Estrada has belonged to the Duque de Estrada family since then.
Many branches of Estrada and Duque have evolved without relationship to each other or the Duque de Estrada surname.
Family members emigrated to the americas at different times.