heir in 1312 temporarily improved EdwardII's position in relation to the baronial opposition. To bolster further the independent prestige of the young prince, the king had him created Earl of Chester at only twelve days of age. 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. Early reign (1327–1337) Mortimer's rule and fall It was not long before the new reign also met with other problems caused by the central position at court of Mortimer, who was now the de facto ruler of England. Mortimer used his power to acquire noble estates and titles, and his unpopularity grew with the humiliating defeat by the Scots at the Battle of Stanhope Park in the county of Durham, and the ensuing Treaty of Edinburgh–Northampton, signed with the Scots in 1328. Also the young king came into conflict with his guardian. Mortimer knew his position in relation to the king was precarious and subjected Edward to disrespect. The tension increased after Edward and Philippa, who had married at York Minster on 24 January 1328, had a son, Edward of Woodstock, on 15 June 1330. Eventually, the king decided to take direct action against Mortimer. Aided by his close companion William Montagu, 3rd Baron Montagu, and a small number of other trusted men, Edward took Mortimer by surprise at Nottingham Castle on