Thus, the Vandals crossed the Rhine in 406, the Pyrenees in 409, the Straight of Gibraltar in 428, and established the Vandal Kingdom in Northern Africa and the Western Mediterranean islands by the mid-5th century; the Suebi, initially moving alongside the Vandals, established their Western Iberian kingdom in 409; the Visigothic Kingdom was initially established by treaty in 418 in the Garonne Valley, and soon expanded into the Iberian Peninsula; the Alemanni expanded into Alsace and beyond, from their initial base in the "Agri Decumates"; in the 440s, the Kingdom of the Burgundians was established around the Rhone; an autonomous Kingdom of Soissons was carved out from 457 by Roman military commanders between the Seine and Somme rivers; last but not least, the Franks, which had been established north of the Rhine in 358 by treaty with Emperor Julian, expanded into what is now Belgium and Northern France. As a consequence, when the last Western Emperor Romulus Augustulus was deposed by military commander Odoacer in 476, his direct rule did not extend much beyond the current Northern borders of Italy. Another military leader, Julius Nepos, briefly Romulus Augustulus's predecessor, held territory in Dalmatia and kept the Imperial title until his assassination in 480.