The imperial unification was caused by several facts, in the first instance the Islamic forces in Africa and Baetica were strong and able to defeat the kingdoms one by one. With this, the many kingdoms of the Iberian Peninsula were forced to join forces against the Muslims in the Baetica by 721. This starts a 40 year continuous campaigning led by Malaca and Emerita against the Islamic Emirate of Maghreb, later of Sebta and finally the Emirate of Ishbiliyya. With this, the Spanish community grew and people of Legio, Malaca and Emerita were openly friendly with each other. By the end of the Golden age of the Sadiq Emirate of Ishbiliyya the King Rodericus I of Malaca started the idea of the foundation of a new empire centered again in Toletum, the Hispanian empire.
in 753 the King of Mallaca had managed to make Olisipo and Emerita join the Empire forming the empire's core and successfully starting the empire as he established in Toletum the capital. In 755 Legio joined and in 758 Barcino joined. The last state to join was Narbona which joined in 759 pressured by the Frankish expansionism. The empire was mainly a federated group of states not too different from the OTL HRE with the difference of being a centralized empire of the Spanish rather than the Hispano-Romanic or Germanic population.