was it ever dissolved?
Yes, the King's Bench ceased to exist
Court of King's Bench (England)
he King's Bench thus ceased to exist, holding its last session on 6 July 1875, except as the King's Bench Division of the High Court. 
where did the trial of lord george gordon happen? Court of King's Bench when did it happen? 5 February 1781 why was he on trial? High treason; Gordon's role in the eponymously named riots where is the court located? England can you name some of its official? Chief Baron of the Exchequer
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Court of King's Bench (England) [SEP] Dissolution
The existence of the same courts under one unified head was a quirk of constitutional law, which prevented the compulsory demotion or retirement of Chief Justices. By sheer chance, both the Chief Justice of the Common Pleas and Chief Baron of the Exchequer died in 1880, allowing for the abolition of the Common Pleas Division and Exchequer Division by Order in Council on 16 December 1880. The High Court was reorganised into the Chancery Division, King's Bench Division and the Probate, Divorce and Admiralty Division; the King's Bench (now Queen's Bench) division remains to this day as lord .