Richard was very wealthy and used it to be elected Holy Roman Emperor. His reign was not of any substance-pretty much symbolic. Late in life he gave up hope of ever actually ruling.
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Richard, Count of Poitou by 18 Aug 1225 (renounced c Dec 1243), 1st Earl of Cornwall, so styled from 21 Aug 1227 and King of the Romans (ie. heir presumptive to the Holy Roman Empire), so elected at Frankfurt 13 Jan 1256/7 and crowned at Aachen 17 May 1257 but soon ejected and returned to England, three of the Electors apparently having thrown him over because his monetary inducements to them were too small, PC (1253); Constable of Wallingford Castle 1216; knighted Feb 1224/5 and granted by his brother Henry III 13 Feb 1224/5 the County of Cornwall during the King's pleasure, following which he was presumably invested as Earl of that county; Lt of Guienne 1226-7; Ambassador to Holy Roman Emperor Frederick II 1237 and Popes Innocent IV and Alexander IV 1250 and 1259 respectively; went on Crusade 1240-41; Co- or sole Regent during his brother Henry III's campaigns in Gascony 1253-54, fought with his brother Henry III against Simon de Montfort's barons at Battle of Lewes 1264, where he was captured; married 1st 30 March 1230/1 Isabel, 3rd daughter of William Marshal, 1st Earl of Pembroke and widow of Gilbert de Clare, 5th Earl of Hertford and 2nd Earl of Gloucester, and had three sons (all died young or sp); married 2nd 22 Nov 1243 Sancha, sister of his brother Henry III's wife Eleanor and 3rd daughter and coheir of Raymond Berengar V, Count of Provence, and by her had two or three sons (also died young or sp, including the 2nd and last Earl of Cornwall); married 3rd 16 June 1269 Beatrice, 2nd daughter of Walram de Fauquemont (or Valkenberg, near Mastricht), Seigneur de Montjoie and brother of Engelbert Archbishop of Cologne, and died 2 April 1272, leaving by Jeanne de Valletort, an illegitimate son. [Burke's Peerage]