Image copyright EPA

An independent report has found that at least 1,400 children were sexually exploited in Rotherham by gangs of men who were predominantly of Pakistani origin between 1997 and 2013.

Report author Professor Alexis Jay said that girls as young as 11 were raped by "large numbers of male perpetrators".

It spoke of the "collective failures" of political, police and social care leadership over the first 12 years the inquiry covered.

These are the key developments of the past two decades.

Early to mid 1990s

Community workers come across examples of child sexual exploitation during this period, according to the new report. It was known that children under the care of the local authority were at risk of being targeted.

1997

The Risky Business youth project is set up to work with people between the ages of 11 and 25 in Rotherham amid concerns about young people being abused through prostitution. By the late 1990s it starts to identify vulnerable girls and young women on the streets of the town, and refers to children's social care any young person who causes serious concerns.

Early 2000s

A small group of professionals from key agencies meet children at risk of, or involved in, child sexual exploitation (CSE) but their work is not properly supported, according to the report. Some of those at a senior level in children's social care and in the police think youth workers are exaggerating the extent of the issue.

2002

A chapter of a draft report into CSE in Rotherham - referred to as The Home Office Report - contains severe criticisms of agencies working to tackle such crimes. It shows there is a "high prevalence of young women being coerced and abused through prostitution".

Senior officers at the council and in the police are unhappy with The Home Office Report, with the suggestion some facts are either exaggerated or made up. The researcher writing the report does not complete her work. However the Jay report says the content which was objected to has been shown to be "largely accurate".

The Jay report states: "Had this [2002 draft] report been treated with the seriousness it merited at the time by both the police and the council, the children involved then and later would have been better protected and abusers brought to justice."

Rotherham abuse 1,400 children were abused, 1997-2013 1/3 of victims were already known to social services

157 reports concerning child sexual exploitation made to police in 2013

10 prosecutions were made between 2013 and April 2014 Getty

August 2003

A report by strategic drugs analyst Dr Angie Heal, commissioned by South Yorkshire Police, finds there are a "significant number of girls and some boys who are being sexually exploited" in Rotherham.

In a later report, in 2006, Dr Heal describes the situation continuing "as it has done for a number of years" with an organised and established sexual exploitation scene.

September 2003

The Area Child Protection Committee approves revised procedures relating to the sexual exploitation of children.

The Sexual Exploitation Forum is set up later in 2003, holding monthly meetings to discuss cases of children who are being sexually exploited or are at risk.

November 2004 and early 2005

Presentations on CSE are made to the council's children's executive group, the children and young people's board and the safeguarding board. An action plan is called for.

April 2005

A seminar on CSE is held for all council members. A new department of children and young people's services is created with Councillor Shaun Wright appointed cabinet member for the department.

June 2005

The Sexual Exploitation Forum is discussing more than 90 cases and it is decided that the number being considered should be reduced. This followed an audit of 87 CSE cases carried out by police on behalf of the forum.

April 2007

An investigation into the grooming and sexual abuse of young boys identifies more than 70 alleged victims. A man is convicted of offences against 10 children.

December 2007

The forum learns that Risky Business is "inundated" with referrals, all of them relating to young people under the age of 18, and some of whom are in care. Risky Business is said to be under pressure from those who referred the children.

2008

Operation Central is set up to investigate men believed to be involved in child sexual exploitation. Funding for Risky Business is increased.

Autumn 2009

Ofsted rates Rotherham's children's services as "inadequate" as the safety of children cannot be assured.

December 2009

The minister of state for young people and families serves the council with an improvement notice for its children's safeguarding services. It is lifted in January 2011.

April 2010

The local Safeguarding Children Board sets up a child sexual exploitation sub group.

Image copyright Other Image caption Five men were convicted for sexual offences against girls in 2010

November 2010

Five men from Rotherham's Asian community are jailed for sexual offences against teenage girls.

September 2012

The Times publishes an investigation revealing that a confidential 2010 police report had warned thousands of child sexual exploitation crimes were being committed in South Yorkshire each year by networks of Asian men.

The newspaper also reports that police and child protection agencies in the town of Rotherham had extensive knowledge of such crimes for decades, yet offences went unprosecuted. South Yorkshire Police denies withholding information and says the suggestion it was reluctant to tackle child sexual abuse is wrong.

October 2012

Rotherham Borough Council, South Yorkshire Police and other agencies set up a CSE team to investigate the issues raised in the report.

The police force denies it had been reluctant to tackle child sexual abuse but the Home Affairs Select Committee tells the chief constable and one of his top officers to "get a grip" on the issue.

January 2013

Image copyright PA Image caption Council chief executive Martin Kimber apologises to young people who were "let down"

The chief executive of the council appears before the Home Affairs Select Committee to answer questions about the lack of prosecutions, with chairman Keith Vaz saying the council had not done enough since the 2010 prosecutions.

Council chief executive Martin Kimber blames "systematic failures" as he apologises to victims and their families.

August 2013

South Yorkshire's Police and Crime Commissioner Shaun Wright announces three reviews of child sexual abuse in the South Yorkshire Police area.

Four women sue the council for failing to protect them when they were children.

September 2013

The council announces it is commissioning an independent inquiry. It is later announced that Professor Alexis Jay will lead the inquiry team.

26 August 2014

Professor Alexis Jay's report is published. Rotherham Borough Council leader Roger Stone steps down with immediate effect. Mr Wright says he will stay in his job as police commissioner despite calls for him to stand down.

28 August 2014

Education Secretary Nicky Morgan announces Ofsted will carry out an early inspection of child protection services in Rotherham.

2 September 2014

Image copyright PA Image caption Shaun Wright faced pressure to stand down as crime commissioner

South Yorkshire Police commissions an independent investigation into its handling of the Rotherham child sexual exploitation scandal. The inquiry will examine the role of both the police and council.

South Yorkshire's Police and Crime Commissioner (PCC) Shaun Wright is told he will have to face questions about the failings of both the police and council by a committee of MPs.

An urgent question is tabled in the House of Commons by Yvette Cooper MP - Labour's shadow home secretary - on the issue.

Meanwhile, the Labour Party suspends four of its members - including Rotherham councillors and former councillors - pending an investigation. The four people suspended are named as former leader of the council Roger Stone, ex-deputy council leader Jahangir Akhtar, Gwendoline Russell, and Shaukat Ali.

Home Secretary Theresa May announces the government is considering carrying out an inspection of Rotherham Council in the wake of the child abuse scandal.

8 September 2014

The chief executive of Rotherham Council Martin Kimber says he will step down at the end of December.

In a statement, he said he wanted to reiterate his "sincere apology to those who were let down".

9 September 2014

Image caption Shaun Wright gives evidence to the Home Affairs Select Committee

The police and crime commissioner for South Yorkshire, Shaun Wright, tells the Home Affairs Select Committee he was not aware of the scale of the abuse problem in Rotherham while a Labour councillor in the town.

He tells the committee he had received a report in 2007 outlining some cases.

However, he said he "did not recall it indicating the scale of child sexual exploitation at that time".

10 September 2014

Local Government Secretary Eric Pickles announces that Rotherham Council will face an independent inspection led by Louise Casey, the head of the Government's troubled families programme, which will examine whether the council covered up information about the abuse.

16 September 2014

Shaun Wright resigns from his role as South Yorkshire's Police and Crime Commissioner.

Mr Wright, who was the head of children's services in Rotherham between 2005 and 2010, said he was stepping down to ensure the "important issues" outlined in the Jay Report could be discussed and considered "without distraction".

19 September 2014

Image copyright PA Image caption Joyce Thacker was paid £40,000 to leave her role at Rotherham Council

Rotherham council's director of children's services Joyce Thacker announces her resignation.

The council said Ms Thacker "is to leave... by mutual agreement, with immediate effect".

It later emerges she was paid £40,000 to leave in the wake of the Jay Report.

13 October 2014

The National Crime Agency (NCA) says it is to lead an investigation into outstanding allegations of child sexual exploitation in Rotherham.

The NCA said it was taking on the investigation, known as Operation Stovewood, following a request from South Yorkshire Police last month.

23 October 2014

South Yorkshire Police says it has referred 14 members of its staff to the police watchdog, the Independent Police Complaints Commission (IPCC), and there may be more.

18 November 2014

The Independent Police Complaints Commission (IPCC) says it is to investigate 10 South Yorkshire Police officers over the handling of child sexual exploitation in Rotherham.

The officers are 10 of those referred to the IPCC by the force.

19 November 2014

Image copyright Getty Images Image caption Children's services in Rotherham are "inadequate", Ofsted says

Ofsted warns "widespread or serious failures" at Rotherham Council are leaving young people at risk of harm, after an inspection by the watchdog rated the authority's children's services as "inadequate".

The new report says management had not sufficiently understood the failures or been effective in making improvements.

Rotherham Council says it "fully accepted" the findings of the report.

5 January 2015

Ian Thomas starts work as the new director of children's services at Rotherham Council.

4 February 2015

Image caption Louise Casey, director-general for troubled families at the Communities Department, says Rotherham Council was "not fit for purpose"

A report by Louise Casey says Rotherham Council is "not fit for purpose" prompting Eric Pickles to announce plans to hand control of the council to a team of five commissioners.

Following the publication of the report, council leader Paul Lakin announces he will resign with immediate effect. The council's cabinet says it will stand down as soon as transitional arrangements are put in place.

The National Crime Agency (NCA) says the latest report has identified "a number of potentially criminal matters".

Files passed to the NCA relate to one former and one existing councillor arising from the inquiry, Ms Casey's spokesperson says.

Alan Billings, who was appointed as Police and Crime Commissioner (PCC) for South Yorkshire following Shaun Wright's resignation, says an advisory panel, including survivors and family members, is being set up to ensure police and social services are doing what they said they were.

5 February 2015

The interim chief executive of Rotherham Council, Jan Ormondroyd, apologises for its failure to act over the scandal of child sexual exploitation in the town.

10 February 2015

John Goldup, Ofsted's former deputy chief inspector and national director of social care, tells MPs government inspectors lacked the focus to target child abuse in Rotherham because they had a "limited" understanding of it.

Mr Goldup tells the Communities and Local Government Committee: "We did not get it right on child sexual exploitation in Rotherham... and I apologise for that."

26 February 2015

Sir Derek Myers, Stella Manzie, Malcolm Newsam, Mary Ney and Julie Kenny are named as the five government-appointed commissioners who will take over the running of Rotherham council.

10 and 11 March 2015

Image copyright PA Image caption Former Rotherham Council leader Roger Stone appears before the Communities and Local Government Committee

Former Rotherham Council leader Roger Stone, who stood down following the publication of the Jay Report, appears before the Communities and Local Government Committee.

Mr Stone tells MPs he rejects allegations he was a "bully" who had fostered a "macho culture" at the authority.

The following day, he says Lousie Casey's damning report into the failures of the authority felt "like a witch hunt".

17 March 2015

The Communities and Local Government Committee publishes a report saying government inspectors failed to detect child sexual exploitation in Rotherham because they trusted council staff.

26 March 2015

The Independent Police Complaints Commission says it is investigating complaints against 42 South Yorkshire Police officers over the handling of child sexual exploitation in Rotherham.

The police watchdog reveals it has received 30 complaints, making more than 100 allegations.