This judge and the other two heads of divisions (Family and King's Bench) sit by virtue of their offices often, as and when their expertise is deemed relevant, in a panel in the Court of Appeal.
Partly due to the old system of many pre-pleadings, pleadings, and hearings before most cases would reach Chancery the expense and duration of proceedings was pilloried in art and literature before the reforms of the late 19th century.
The holder nominally acted as the Lord Chancellor's deputy in the English legal system and as head of the Chancery Division.
Because of an increase in caseload in the Court of Chancery for its two judges (the Lord Chancellor and the Master of the Rolls), an additional judicial office, the Vice-Chancellor of England, was created by the Administration of Justice Act 1813 to share the work.
The caveat was lifted by section 52 of the Master in Chancery Abolition Act 1852, so the number became fixed at three until the next major court reforms.