Lets add some flavor to the topic:
Euric(466 - 484) first ruler of Visigothic Spain
Unlike his predecessor Teodoric II, Euric was declared anti - roman. He was not fluent in latin, and mostly used translators for negotiations with imperial envoys. He was also convinced and devoted arian, full of gothic pride and awareness of glory of his ancestors. With politic full of wisdom and carefulness he fought sucesfully Bretones(469), occupied Aquitania Prima and conquered temporarily Arles, Avignon and Valance(474/5).
From legal point of view, Euric was first independent ruler of Visigothic kingdom, because only to him emperor Iulius Nepos(475) confirmed full souvereignity. During his rule, kingdom reached peak of territorial power; from Loara on north to Rhone on the East, provence and almost entire Spain. In any case, by confirmation of Iulius Nepos, Euric legalized his conquests and state.
Sidonius Apolinar is resignated and somehow insulted by these conquests. As a declared Roman he writes:
There are rumors that Goths came to our lands. We, unlucky Alvernians are always on the roads of such invasions. That, what especially motivates our enemies is the fact that we are the bareer with Christs's help, to their ambitions to establish their borders to Ocean. Loara and Rhone...But we do not expect that our resistance, so brave and risky will still be supported by our walls on fire and already demolished, or our rotten palisades or already weak chests of our guards...
Strength of Euric's kingdom could be seen by even most convinced romanophiles. the core of that state, beside extremely developed court and competent ruler was also Aquitaine and Pamplona, areas very rich with fertile land. Even Salvian had to admit this:
Everyone knows that Aquitaine and Pamplona are the hearts of the whole Gallia, that land there is magically fertile and full of pleasure, magics and joys. Everything is full of wineyards, decorated with pastures, cultivated in fertile fields, overshadow by small forests, rich with water and covered by waving crops and wheat, so it seems like owners are not taking their parcelles apart, but all is a picture of Heaven.
The future of Visighotic kingdom will after all not be in this fertile region of Gallia. Klodoveg's Franks and death of Euric's son Allaric II( 484 - 507) in battle of Vouille will force Visigoths to move the center of their kingdom in Spain.
Battle of Vouillee (507)
Klodoveg and his Franks were proclaimed defenders of catholicism Supported maybe even by eastern emperor Anastasius I(491 - 518) Klodoveg assembled his armies and marched into Visighotic lands, and at the north of their kingdom, somehwere around unknown city of Vocladum, gained great victory.
The defeat of Visighots was catastrophic. among corps left on the battlefield: hills of corps according to Venancius Fortunatus, there was also a corp of king, Alaric II. The whole Aquitaine between Loara and Garona was easily subjugated to new masters - Franks. Only Septimania was left to Visighots and earlier conquered Spain, and there, Visighots will establish new state.
After Franks took power in Gallia, Visigoths were forced to move to Spain. In waves, this colonization lasted from 507 - 535, and at the time was very violent. All arian churches on territories of Frankish kingdom were closed, and after 534, according to Zaragoza Chronicles, all Visigoths moved to Spain or area under their control around Narbona. For vast Spain along with Narbonian area, Visigoths were still too small people, who made only 2,5 to 3% of entire population. Their settlements were most densely populated in northwest between Tajo on south and Pamplona on north. From the west, these settlements were established from Catajuda to Salamanca. Rest of the peninsula knew only for their guards and military stations in bigger towns.
On "their" areas, Visighots forcefully took 2/3 of land from hispano - roman nobles, and shared it between themselves as sortes goticae. The land left to original owners was called tertiae Romanorum. These words are still alive today in some toponims like Sort, Consortes, Tercia, Terciar, Godos, Campos Goticos or Burgos.
Although they saved ethnic composition, Visigoths were rapidly assimilated in cultural sense by native, romanized population. They lost all their traditions and customs, and their life in Spain hasn't lasted even for 300 years. Later, they moved to Galizia, where they were inhabited in compact groups and entirely romanized.