Before Roman times, the Basque tribes, little organized politically, extended farther to the north and south than at present. But the core of the Basque Country resisted Romanization and was only nominally subject to Roman rule. Christianity was slow in penetrating (3d–5th cent.). Once converted, the Basques remained fervent Roman Catholics, but they have retained a certain tradition of independence from the hierarchies of Spain and France.
The Basques withstood domination by the Visigoths and Franks. Late in the 6th cent. they took advantage of the anarchy prevailing in the Frankish kingdom and expanded northward, occupying present-day Gascony (Lat. Vasconia ), to which they gave their name. The duchy of Vasconia, formed in 601 and chronically at war with the Franks, Visigoths, and Moors, was closely associated with, and at times dominated by, Aquitaine. In 778 the Basques, who had just been reduced to nominal vassalage by Charlemagne, destroyed the Frankish rear guard at Roncesvalles, but they subsequently recognized Louis the Pious, king of Aquitaine, as their suzerain.
The duchy of Gascony continued, but the Basques early in the 9th cent. concentrated in their present habitat and in 824 founded, at Pamplona, the kingdom of Navarre, which under Sancho III (1000–1035) united almost all the Basques. Although Castile acquired Guipúzcoa (1200), Álava (1332), and Vizcaya (1370), the Castilian kings recognized the wide democratic rights enjoyed by the Basques. Guernica was the traditional location of Basque assemblies.
With the conquest (1512) of Navarre by Ferdinand the Catholic, the Basques lost their last independent stronghold. After the 16th cent., Basque prosperity declined and emigration became common, especially in the 19th cent. Basque privileges remained in force under the Spanish monarchy, but in 1873 they were abolished because of the Basques' pro-Carlist stand in the Carlist Wars. To regain autonomy, the Basques supported nearly every political movement directed against the central authority.
In the civil war of 1936–39, the Basque provs., not including Navarre, defended the republican government, under which they had autonomous status; the Basques of Navarre supported the Franco forces. The Franco government, once in power, for the most part discouraged Basque political and cultural autonomy, but Basque nationalism retained its appeal to the Basques, and they continued to wage their fight for self-determination.
Following Spain's return to democracy, limited autonomy was granted to the region, and in 1980 the first Basque parliament was elected. Nonetheless, terrorist activities by the Basque separatist organization, Basque Homeland and Freedom (Euzkadi Ta Azkatasuna; ETA), which had begun in 1968, continued, ultimately killing about 800 people by the end of the 1990s, many of them police officers and soldiers. From 1983 to 1987 a secret government-sponsored death squad killed 27 and wounded about 30, most members of the ETA.
Basque nationalism, often involving unrest and violence by and against the ETA, has continued, but Basque terrorists and a separatist party lost some popular support in the 1990s. In 1996, Spanish and French officials agreed on joint measures to crack down on the terrorist group; a cease-fire (1998–99) by the ETA failed to lead to a peace accord. In 2001, Basque nationalist candidates won more than 50% of the vote in the regional parliamentary elections, but only about 10% supported the party aligned with the ETA. In 2002 that political party, then called Batasuna, was accused of collaborating with the ETA and suspended for three years; it was permanently banned the following year, and its leaders arrested in 2007. The ETA announced a "permanent" cease-fire in Mar., 2006, and the government subsequently agreed to talks. Few talks and no progress had occurred when a Dec., 2006, bombing in Madrid ended the talks, and six months later the ETA officially ended its ceasefire. A new cease-fire by the ETA, announced in Sept., 2010, after requests from Basque nationalist parties, was regarded skeptically by the Spanish government, which called on the ETA to disarm and disband. In Oct., 2011, the ETA declared an end to its armed campaign.
Moderate Spanish Basque nationalists have sought increased autonomy for the region. The Basque parliament approved a plan for "free association" with Spain in 2004, but it failed to win the approval of the Spanish Cortes. In 2009 Basque nationalists failed to win a majority in parliament, and the Socialist and Popular parties formed the regional government, but in 2012 the nationalists won a plurality. There is also strong support among French Basques for political automony.