The Sleaford and North Hykeham by-election was a by-election in England for the House of Commons constituency of Sleaford and North Hykeham held on 8 December 2016.
 It was triggered by the resignation of Conservative MP Stephen Phillips on 4 November 2016.
 It was the first by-election to be contested in Lincolnshire since the Lincoln by-election of 1973 which by coincidence back then also saw the UK's relationship with Europe being a major issue.
The Rotherham by-election was a by-election for the Parliament of the United Kingdom's House of Commons constituency of Rotherham.
 The by-election was caused by the resignation of its Member of Parliament Denis MacShane after the House of Commons Standards and Privileges Committee found that he had submitted 19 false invoices "plainly intended to deceive" the parliamentary expenses authority, an issue dating back to 2009 and a wider parliamentary expenses scandal in the UK.
 MacShane accepted the office of Steward and Bailiff of the Chiltern Hundreds on 5 November 2012, formally vacating his seat.
 The election took place on 29 November 2012, at the same time as by-elections in Croydon North and Middlesbrough which were caused by the deaths of the sitting MPs.
Liam Burke (2 February 1928 – 21 August 2005) was an Irish Fine Gael politician.
 He was a Teachta Dála (TD) for the Cork North-Central constituency.
 Burke was first elected to Dáil Éireann at the 1969 general election for Cork City North-West.
 After the constituencies were redrawn, he stood at the 1977 general election in the new Cork City constituency, but lost his seat.
 He was returned to the 21st Dáil at a by-election on 7 November 1979 in the same constituency, following the death of the Labour Party TD Patrick Kerrigan.
 That by-election win contributed to the decision of then Taoiseach Jack Lynch to resign in December 1979.
Bishop Isidore Borecky (Ukrainian: Ісидор Ілярій Борецький ; 1 October 1911 in Ostrivets, Austro-Hungarian Empire (present day in Terebovlia Raion, Ternopil Oblast, Ukraine) – 23 July 2003 in Toronto, Canada) was a Ukrainian-born Canadian Ukrainian Greek Catholic hierarch.
 He served as the Titular Bishop of Amathus (until 3 November 1956) and the first Eparchial Bishop of the new created Ukrainian Catholic Eparchy of Toronto from 17 January 1948 until his retirement on 16 June 1998 (until 10 March 1951 with title of Apostolic Exarch of Eastern Canada; and until 3 November 1956 with title of Apostolic Exarch of Toronto).
The Aberdare by-election, 1946 was a parliamentary by-election held on 5 December 1946 for the British House of Commons constituency of Aberdare in Wales.
 The seat had become vacant when the Labour Member of Parliament (MP) George Hall had been created Viscount Hall on 28 October 1946.
 Hall had held the seat since the 1922 general election.
 The Labour candidate, David Thomas held the seat for the party.
 He remained the constituency's MP until his death in 1954, when a further by-election was held.
The City of Chester by-election of 15 November 1956 was held after the appointment of Conservative Member of Parliament (MP) Basil Nield as Recorder of Manchester.
Ajay Rai is an Indian politician and member of Uttar Pradesh Legislative Assembly.
 He is a five-time MLA from Uttar Pradesh.
 A local strongman in the Varanasi area, Rai began his political career as a member of the Bharatiya Janata Party's student wing.
 He won the Legislative Assembly elections from the Kolasla constituency three times in a row between 1996 and 2007 on a BJP ticket.
 He left the party after being denied a Lok Sabha ticket.
 He then joined the Samajwadi Party and unsuccessfully contested the 2009 Lok Sabha elections.
 Subsequently, he won the 2009 Legislative Assembly by-election from the Kolasla constituency as an independent.
 He then joined the Indian National Congress.
 After the Kolasla constituency ceased to exist post-delimitation, he won the 2012 Assembly elections from the newly created Pindra constituency, which comprises a sizeable portion of the former Kolasla constituency.
The 2009 Glasgow North East by-election was a by-election for the Parliament of the United Kingdom's House of Commons constituency of Glasgow North East.
 The by-election was held on 12 November 2009 following the resignation of Michael Martin as an MP and as Speaker of the House of Commons following the MPs' expenses scandal.
 Martin was the first Speaker since Sir John Trevor in 1695 to be forced from office.
 Willie Bain, the Scottish Labour Party candidate, won with 59% of the vote.
 Just 33% of the electorate voted, which is the lowest ever percentage turnout in a Scottish by-election to the House of Commons.
The Croydon North by-election was a by-election for the Parliament of the United Kingdom's House of Commons constituency of Croydon North in the London Borough of Croydon.
 The by-election was caused by the death of its Member of Parliament Malcolm Wicks.
 It took place on Thursday, 29 November, the same day as by-elections in Middlesbrough and Rotherham.
 The by-election was won by Steve Reed of the Labour Party.
The City of Chester is a constituency created in 1545 (turned into a county division in 1885 and reformed in narrowed geographical guise in 1918) and represented in the House of Commons of the UK Parliament since 2015 by Chris Matheson of the Labour Party.

Question: When was the constituency which its by-election was on15 November 1956 created 
Answer: 1545