The Gallaeci were the Celtic tribal confederation that inhabited the territory stretching from the Douro river to the Cantabrian coast — the land the Romans would name Gallaecia, and that we know today as Galicia. Greek geographer Strabo described them as "the most warlike of all the Lusitanian peoples," a confederation of dozens of smaller groups (populi) united by a common language, material culture, and the distinctive settlement pattern of the castros — fortified hilltop villages that defined the landscape of northwestern Iberia for nearly a millennium.

Among these populi, the Querquerni and Coelerni inhabited the middle Miño valley and the territory around the Arnoia river in what is now Ourense province — precisely the ancestral homeland of the Álvarez and Rodríguez families in Castrelo de Miño and Cartelle. These tribes lived in circular stone dwellings within fortified hilltop enclosures, practiced metalworking in gold and bronze, raised cattle, and cultivated the sheltered river valleys. The Gallaeci fiercely resisted Roman expansion; it took Rome over a century of campaigns to subdue them, from Decimus Junius Brutus Callaicus in 137 BC to Augustus during the Cantabrian Wars (29–19 BC).

The word "Castrelo" itself is a direct inheritance from the Celtic past. It derives from the Latin "castrum" (fortress), which Romans used to designate the native hilltop settlements they encountered. The municipality of Castrelo de Miño was named for the ancient Castrum Minei — the castro that commanded the strategic river crossing of the Miño. This is no isolated case: across Ourense province, hundreds of place names encode Celtic and Castro-period origins. Every toponym beginning with "Castro-" or "Castrelo-" marks the site of a former hillfort. The suffixes "-briga" (fortified height) and "-dunum" (fortress) appear throughout Galicia — Nemetobriga, the sacred grove-fortress near Trives, and Brigantium (modern A Coruña) are among the most prominent.

In the family's ancestral parishes, the Celtic imprint runs deep. The Arnoia river, flowing through Cartelle, bears a pre-Roman hydronym of probable Celtic origin. The density of "castro" place names in the Ourense river valleys — Castro de Macendo, Castro de Outeiro, Castro das Cavadas — is among the highest in all of Iberia, reflecting the intense settlement of the Gallaeci in this region. Parish names containing elements like "-riz" (from later Germanic overlay) and "-edo/-ido" (Latin suffixes applied to Celtic root words) create a layered etymological record that traces continuous habitation from the Iron Age through the present day.

The physical evidence of Celtic life surrounds the family's ancestral parishes. Castro de Santa Lucía in Astariz, a parish of Castrelo de Miño, is a 2.75-hectare fortified settlement first excavated by the University of Vigo in 2016. Archaeologists uncovered circular stone dwellings characteristic of the Castro culture alongside later rectangular Roman-era structures — a visible record of the transition from Celtic to Roman life. A rock-cut wine press discovered at the site, dated to approximately 235 AD, provides the earliest evidence of winemaking in the Ribeiro region. Castro de Las Cavadas, the legendary Castrum Minei, once commanded the Miño river crossing, while Castro de Macendo and Castro de Outeiro formed a defensive network stretching along the Miño between Ourense and Ribadavia.

The crown jewel of the region's archaeological heritage is the Cidade de San Cibrán de Lás (Lansbrica), located between San Amaro and Punxín — just 18 km from Ourense. At approximately 10 hectares, it is the largest castro in all of Galicia, with two concentric oval walls, organized streets and drainage, over 50 excavated dwellings, and a ritual sauna (pedra formosa). At its peak around the 1st century BC, some 3,000 people lived within its walls. Nearby Castromao, identified as the ancient Coeliobriga and capital of the Coelerni tribe, yielded the famous Tabula Hospitalitatis — a bronze pact dated to 132 AD between the Coelerni and a Roman prefect, one of the most important epigraphic documents of Roman Gallaecia. The Ourense gold torcs, a pair of magnificent Iron Age neck rings found near the city and now in the British Museum, exemplify the metallurgical mastery of the Gallaeci.

The gaita gallega — the Galician bagpipe — is the most visible thread connecting Galicia to the broader Celtic world. Directly related to the bagpipe traditions of Scotland, Ireland, Brittany, and Asturias, the gaita has been the voice of Galician identity for centuries. Galicia is recognised as one of the Celtic nations in cultural terms, participating in the Festival Interceltique de Lorient alongside Ireland, Scotland, Wales, Cornwall, Brittany, and the Isle of Man. Traditional circular dances (muiñeiras) echo pre-Roman communal celebrations. Castrelo de Miño itself maintains a school of bagpipes and tambourines, ensuring this ancient musical tradition passes to new generations.

The Celtic inheritance extends far beyond music. The hórreo — the raised stone granary found throughout Galicia — descends directly from Castro-era grain storage structures, preserving a design principle over two millennia old. Communal land management practices in rural parishes recall pre-Roman collective organisation. The carballeira (sacred oak grove) served as a communal gathering place, mirroring the Celtic reverence for sacred groves documented across Europe. Galician folklore preserves unmistakable pre-Christian elements: the meigas (healers and seers), the Santa Compaña (a spectral procession of the dead that walks the night roads), and the traditions of Samhain — the Celtic new year — which survives in Galicia as the night of departed souls. The Galician language itself retains Celtic substrate vocabulary not found in other Romance languages.