Until James I died in 1625, Buckingham was the king's constant companion and closest advisor, enjoying control of all royal patronage.
Buckingham used his influence to prodigiously enrich his relatives and advance their social positions, which soured public opinion towards him.

In his rise to power, Buckingham became connected with the philosopher and jurist Francis Bacon.
Bacon wrote letters of advice to the young favourite and drafted the patent of nobility when Buckingham ascended to the peerage.
With Buckingham's support, Bacon was appointed Lord Chancellor in 1618.
In gratitude, Bacon honoured Buckingham's many requests for favours from the court for friends and allies.
Following an investigation by Parliament into royal grants of monopoly, financial peculation and corrupt officials, Bacon was convicted of corruption and forced into retirement.
Neither Buckingham nor the King attempted to intervene on Bacon's behalf.
Many of Buckingham's contemporaries believed he had sacrificed Bacon to save himself from Parliamentary scrutiny, as he had been liberally spending public funds and accepting gifts and bribes.

From 1616, Buckingham also established a dominant influence in Irish affairs, beginning with the appointment of his client, Sir Oliver St John, as Lord Deputy, 1616–22.
Thence, he acquired control of the Irish customs farm (1618), dominated Irish patronage at court, particularly with the sale of Irish titles and honours, and (from 1618) began to build substantial Irish estates for himself, his family and clients—with the aid of a plantation lobby, composed of official clients in Dublin.
To the same end, he secured the creation of an Irish Court of Wards in 1622.
Buckingham's influence thus crucially sustained a forward Irish plantation policy into the 1620s.

When Parliament began its investigation into monopolies and other abuses in England, and later Ireland in 1621, Buckingham made a show of support to avoid action being taken against him.
However, the king's decision to send a commission of inquiry to Ireland, that included parliamentary firebrands, threatened to expose Buckingham's growing, often clandestine interests there.
Knowing that the king had assured the Spanish ambassador that the Parliament would not be allowed to imperil a Spanish matrimonial alliance, he therefore surreptitiously instigated a conflict between the Parliament and the king over the Spanish Match, which resulted in the Parliament's premature dissolution in December 1621 and a hobbling of the Irish commission in 1622.
Irish reforms introduced in 1623–24 by Lionel Cranfield, Earl of Middlesex and Lord Treasurer, were largely nullified by Middlesex's impeachment and disgrace in the violently anti-Spanish 1624 parliament—spurred on by Buckingham and Prince Charles.
Until James I died in 1625, Buckingham was the king's constant companion and closest advisor, enjoying control of all royal patronage. Buckingham used his influence to prodigiously enrich his relatives and advance their social positions, which soured public opinion towards him.
In his rise to power, Buckingham became connected with the philosopher and jurist Francis Bacon. Bacon wrote letters of advice to the young favourite and drafted the patent of nobility when Buckingham ascended to the peerage. With Buckingham's support, Bacon was appointed Lord Chancellor in 1618. In gratitude, Bacon honoured Buckingham's many requests for favours from the court for friends and allies. Following an investigation by Parliament into royal grants of monopoly, financial peculation and corrupt officials, Bacon was convicted of corruption and forced into retirement. Neither Buckingham nor the King attempted to intervene on Bacon's behalf. Many of Buckingham's contemporaries believed he had sacrificed Bacon to save himself from Parliamentary scrutiny, as he had been liberally spending public funds and accepting gifts and bribes.
From 1616, Buckingham also established a dominant influence in Irish affairs, beginning with the appointment of his client, Sir Oliver St John, as Lord Deputy, 1616–22. Thence, he acquired control of the Irish customs farm (1618), dominated Irish patronage at court, particularly with the sale of Irish titles and honours, and (from 1618) began to build substantial Irish estates for himself, his family and clients—with the aid of a plantation lobby, composed of official clients in Dublin. To the same end, he secured the creation of an Irish Court of Wards in 1622. Buckingham's influence thus crucially sustained a forward Irish plantation policy into the 1620s.
When Parliament began its investigation into monopolies and other abuses in England, and later Ireland in 1621, Buckingham made a show of support to avoid action being taken against him. However, the king's decision to send a commission of inquiry to Ireland, that included parliamentary firebrands, threatened to expose Buckingham's growing, often clandestine interests there. Knowing that the king had assured the Spanish ambassador that the Parliament would not be allowed to imperil a Spanish matrimonial alliance, he therefore surreptitiously instigated a conflict between the Parliament and the king over the Spanish Match, which resulted in the Parliament's premature dissolution in December 1621 and a hobbling of the Irish commission in 1622. Irish reforms introduced in 1623–24 by Lionel Cranfield, Earl of Middlesex and Lord Treasurer, were largely nullified by Middlesex's impeachment and disgrace in the violently anti-Spanish 1624 parliament—spurred on by Buckingham and Prince Charles.
George Villiers, 1st Duke of Buckingham