In 1325, Edward II was faced with a demand from his brother-in-law, Charles IV of France, to perform homage for the English Duchy of Aquitaine. Edward was reluctant to leave the country, as discontent was once again brewing domestically, particularly over his relationship with the favourite Hugh Despenser the Younger. Instead, he had his son Edward created Duke of Aquitaine in his place and sent him to France to perform the homage. The young Edward was accompanied by his mother Isabella, who was the sister of King Charles, and was meant to negotiate a peace treaty with the French. While in France, Isabella conspired with the exiled Roger Mortimer to have Edward deposed. To build up diplomatic and military support for the venture, Isabella had her son engaged to the twelve-year-old Philippa of Hainault. An invasion of England was launched and EdwardII's forces deserted him completely. Isabella and Mortimer summoned a parliament, and the king was forced to relinquish the throne to his son, who was proclaimed king in London on 25 January 1327. The new king was crowned as EdwardIII at Westminster Abbey on 1February at the age of 14.