Tony Blair's cabinet reshuffle will ultimately lead to the abolition of the ancient post of Lord Chancellor.
Lord Irvine was the 258th lord chancellor
BBC News Online looks at the role, its history and what will replace it.
Lord Falconer will be the 259th lord chancellor during a transition period before the role is abolished
Post is officially Lord High Chancellor of Great Britain and Keeper of the Great Seal
The first was Angmendus in the year 605.
Other incumbents included St Thomas a Becket, St Swithin, Queen Eleanour, Cardinal Wolsey and Sir Thomas More
Origins are the cancellarius - officials who sat at lattice screens separating courts from the public
Modern office - including costume and ceremonial trappings - traced to 11th century
Lord chancellor is custodian of the Great Seal - the chief seal of the Crown, used to show the monarch's approval of important state documents
Great Seal is currently kept in a hidden cupboard
Gained departmental responsibility in medieval times
Post lapsed after Glorious Revolution of 1688
Office returned in 1693
Lord Chancellor's Department established in 1885
Powers expanded in 1972 to include appointment of judges, running court system, tribunals and legal aid.
In 2001, the department assumed responsibility for Human Rights, Freedom of Information, Data Protection, Reform of the House of Lords and other constitutional matters
In 2002 it took over responsibility for Electoral Law, Data Sharing and Party Funding.
Government minister sitting in the cabinet
Judge and also responsible for appointments to judiciary
Speaker of House of Lords
Seen as anomaly to have minister who was also judge and speaker of Lords
Supporters of the move say it will guarantee greater independence for the judiciary
There will also be calls for the new independent appointment body to appoint more female and ethnic minority judges
New department of constitutional affairs replaces the Lord Chancellor's Department
Department headed by Lord Falconer, the new Secretary of State for Constitutional Affairs.
A supreme court will replace the law lords, the final court of appeal for important cases.
A new independent body will appoint judges
New constitutional affairs department will also take on responsibilities of Scottish and Welsh offices
Role of Scottish Secretary taken on by Transport Secretary Alistair Darling
Role of Welsh Secretary performed by new Commons leader Peter Hain
WHAT HAPPENS TO POST OF LORD CHANCELLOR?
Post is to be abolished.
But as the role has some powers which only the lord chancellor can exercise, there must be legislation to transfer such powers to the new Secretary of State for Constitutional Affairs.
Lord Falconer will take on the role of lord chancellor until then.
But unlike his predecessor, Lord Irvine, he will not sit as a judge in the House of Lords.
Judges will no longer sit as politicians.
WHAT HAPPENS TO SPEAKER OF THE LORDS?
He or she will be a non-minister.
Peers will be asked how they want the speaker appointed.
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