Starting as a conservative Catholic movement, Degrelle's Rex party ("Rex" is from Christus Rex, Christ the King) quickly gravitated (like many far-right movements of the 1930s) toward fascism and antisemitism, openly collaborating with the wartime Nazi occupiers (Degrelle even fought alongside the German army, his Walloon Legion later being subsumed into the Waffen-SS). The party remained limited in its appeal (francophone and increasingly extreme) and by that of Flemish separatist rivals in Belgium's northern provinces, never advancing beyond its brief pre-war electoral success (Degrelle's own sister hid three Jewish refugees, surreptitiously serving Jewish dishes to fascist guests), and was banned at the Liberation, many leaders subsequently being executed. Degrelle fled to Spain where he was given sanctuary by the Franco regime, set up in a business that later built local US military bases. Unrepentantly pro-nazi to the last and never brought to justice beyond a fine for Holocaust denial, he died in 1994.

His party Rex was unimportant in Belgium and it's basically due to his political failure that he engaged himself in the Waffen SS on the Eastern Front where he was successful to the extent he received the Ritterkreuz from Hitler himself.

After the war he fled to Spain where he hid protected by the Franco regime and became somehow a superstar among the extreme-right of Europe, especially among the French who saw him as some kind of father figure, a lot of whom considered visiting Degrelle as some kind of pilgrimage; he would received extreme-right youth to his mansion and tell stories and anecdotes for hours (think Abraham Simpsons) and would show off his Ritterkreuz to everyone... he was a very boastful character.