From the Wikipedia page 
Edmund, Earl of Rutland (17 May 1443 – 30 December 1460) was the fifth child and second surviving son of Richard Plantagenet, 3rd Duke of York, and Cecily Neville. He was born in Rouen.
He was created Earl of Rutland by Henry VI probably some time before 1454. No record of the creation has been preserved; Edmund and his older brother Edward, then the Earl of March, signed a letter to their father on 14 June 1454 as "E. Rutland" and "E. Marche."
Lord Chancellor of IrelandEdit
In 1451, Edmund's father, who held the title of Lord Lieutenant of Ireland, appointed Edmund as Lord Chancellor of Ireland. As Edmund was underage, the duties of the position were held by Deputy Chancellors. His first Deputy Chancellor was Edmund Oldhall, Bishop of Meath. His brother Sir William Oldhall was Chamberlain to the Duke of York and was likely behind that appointment. He acted as de facto Chancellor until 1454.
Olldhall was replaced by John Talbot, 2nd Earl of Shrewsbury, who also held the office of Lord High Steward of Ireland. He would continue serving as the de facto Chancellor until his death at the Battle of Northampton (10 July 1460).
His appointment and those of his Deputies were acknowledged by the Parliament of Ireland which at this time first asserted its independence. The Parliament declared that Ireland held separate legislature from England and its subjects were only subject to the laws and statutes of "the Lords Spiritual and Temporal and Commons of Ireland, freely admitted and accepted in their Parliaments and Great Councils".
According to Parliamentary decisions during his term, the Irish subjects were only bound to answer writs by the Great Seal of Ireland, held by the Lord Chancellors. Any officer attempting to enforce the rule of decrees from England would lose all of his property in Ireland and be subject to a fine.
The House of York in Ireland had won the support of Thomas FitzGerald, 7th Earl of Kildare, and James FitzGerald, 6th Earl of Desmond. Several allies of the FitzGeralds followed them in their loyalties. On the other hand the House of Lancaster found its main Irish supporter in the person of James Butler, 5th Earl of Ormonde.