A post on the titles held by Edward II, when he got them, when he gave them up, and some facts about them.
1) Count of Ponthieu and Montreuil, Edward's first title; he inherited it on 28 November 1290, when his mother Queen Eleanor died. He was just six years old, the youngest of his mother's six surviving children, but the only boy. Ponthieu was a small, but strategically important, county in Northern France, bordering Normandy; Montreuil-sur-Mer was its port. Eleanor's nephew Jean, Count of Aumale (died 1302, son of her brother Fernando de Castilla) contested Edward's rights, but he was confirmed as Count in 1299.
To see why the future King of England inherited the county, we need to go back a century, to a huge royal scandal. Alais (Alix/Alice/Alys/Adele), daughter of Louis VII of France, was betrothed to Richard 'the Lionheart'. He repudiated her because she had allegedly borne a child to his father Henry II, imprisoned her for several years, and sent her back to France in 1195. Her half-brother King Philip Augustus promptly married her off to Guillaume IV, Count of Ponthieu. The marriage took place on 20 August 1195, a few weeks before Alais' thirty-fifth birthday; Guillaume was about sixteen. Philip Augustus probably intended the marriage to be childless, which would ultimately give him control of Ponthieu, but Alais gave birth to a daughter, Marie, in April 1199. (There may have been other children, but they didn't survive.) Marie, heiress of Ponthieu, married Simon, Count of Aumale, and their eldest daughter Jeanne de Dammartin succeeded as Countess of Ponthieu in her own right. On Jeanne's death in 1279, her only surviving child by King Fernando III, Eleanor of Castile, Queen of England, became Countess of Ponthieu and Montreuil.
On 14 May 1308, Edward II granted Ponthieu and Montreuil and all their revenues to Queen Isabella. Both of them occasionally used their title in letters: Counte/Contesse de Pontiff et de Monstroill, with a few variations in spelling. On 2 September 1325, at Langdon Abbey, Edward relinquished the title and lands of Ponthieu to his son Edward of Windsor (Edward III), so that the boy could pay homage for the lands to his uncle, Charles IV of France. Charles' successor Philip VI confiscated Ponthieu in the 1330s; it was restored in 1360, confiscated again, and finally passed to the French crown permanently.
2) Prince of Wales. At Parliament in Lincoln on 7 February 1301, Edward I bestowed the title of Prince of Wales on his son. Edward was sixteen years, nine months and thirteen days old. Edward I had completed the conquest of Wales a few years earlier. The title of 'Prince of Wales' had last belonged to Llywelyn ap Gruffydd, who was killed in an ambush by some of Edward's forces in December 1282. His brother Dafydd was hanged, drawn and quartered at Shrewsbury in October 1283; Dafydd's daughter Gwladys, and Llywelyn's daughter Gwenllian, were sent to convents in Lincolnshire, where they died in 1336 and 1337. Dafydd's sons were imprisoned in Bristol Castle. Llywelyn, the elder, died in 1288, but the younger, Owain, lived for many more years - unfortunately for him. In October 1305, Edward I sadistically ordered that Owain be kept in a wooden cage bound with iron at night. He was still alive in 1325.
Edward II was of course born in Caernarfon, and was always rather popular in Wales. 'Prince of Wales' was the one title he never relinquished; Edward III never held the title, and it was next given to Edward of Woodstock, the Black Prince, in 1343. In documents of the early 1300s, Edward of Caernarfon is often referred to as monsieur Edward prince de Gales, fiz nostre seignur le Roi ("Lord Edward, Prince of Wales, son of our lord the king").
3) Earl of Chester, also granted to Edward on 7 February 1301. The earldom had reverted to the Crown on the death of the childless John the Scot, Earl of Huntingdon and Chester, in 1237. In 1254, Henry III passed the lordship of Chester - though not the title of earl - to his elder son Edward, later Edward I. In April and May 1301, Edward of Caernarfon spent a few weeks travelling around his new lands in Cheshire and Wales, receiving the homage and fealty of his new tenants; at sixteen/seventeen years old, he was now a great and enormously wealthy feudal magnate.
Edward II granted the title of Earl of Chester to his son Edward of Windsor on 25 November 1312. Astonishingly, the new earl was a mere twelve days old. Since 1301, the earldom of Chester has always been granted to the heir to the throne, and since 1399, the earldom and the principality of Wales have always been granted together.
4) Duke of Aquitaine: bestowed on Edward in May 1306, when he was twenty-two, though his father continued to use the title for the remaining fourteen months of his life. Edward was knighted on 22 May 1306, and the granting of Aquitaine was presumably intended for him to sustain his new position. He was also granted the island of Oléron and the Agenais. Edward paid homage for his new duchy to his overlord and future father-in-law, Philip IV, at his own town of Montreuil-sur-Mer that year.
The story of English rule over Aquitaine - also known as Gascony or Guyenne - is beyond the scope of this post, but it caused a huge amount of tension and conflict between England and France for centuries. Edward II relinquished the title to his son on 10 September 1325, and the twelve-year-old set off for France to pay homage two days later.
5) King of England, naturally. Edward I died on 7 July 1307, so Edward II's reign dates from 8 July 1307. He was twenty-three; his father was sixty-eight and had been King of England since November 1272. Edward I died at Burgh-by-Sands near Carlisle at around 3pm in the afternoon of the 7th. Edward II, in or close to London, heard the news on the 11th - approximately 315 miles in four days, an interesting illustration of how fast royal messengers could travel in those days.
Edward renounced his throne at Kenilworth Castle on 20 January 1327, to his fourteen-year-old son.
6) Lord of Ireland; Edward also succeeded to this title on 8 July 1307 and gave it up to his son on 20 January 1327. He never visited Ireland (or Aquitaine/Gascony either). On 16 June 1308, forced to exile Piers Gaveston from England, he hit on the solution of making his favourite the King's Lieutenant of Ireland, a position Gaveston filled with some distinction. Roger Mortimer also spent a large part of his career in Ireland, as King's Lieutenant and Justiciar. All the Kings of England from Henry II in 1171 to Henry VIII in 1541 called themselves 'Lord of Ireland'. (Henry VIII upgraded the title to 'King of Ireland', but that's Henry for you.)