John Witherow, the Sunday Times editor, has paid tribute on Radio 4 to Marie Colvin, the paper's journalist killed in Syria, describing her as "one of the greatest foreign correspondents of her generation".
Witherow said Colvin, who was killed in the besieged Syrian town of Homs on Wednesday along with French photographer Remi Ochlik when the building they were in was hit by artillery fire, was an "extraordinary journalist".
He added that she did not just want to report, but "to change things and she believed that reporting could change things and alleviate suffering". "In several cases I think she did achieve that," Witherow told Radio 4's The Media Show.
He said Colvin was sickened to the core about what was going on in Syria and wanted to share it with the rest of the world.
"They are killing with impunity here. It is sickening and angry-making," she wrote in an email just two days ago to the BBC's Jeremy Bowen, Witherow added.
She sent a similar email to Channel 4 international editor Lindsey Hilsum, who said in a blog posting that Colvin told her: "This is the worst thing we have ever seen and they are getting away with it, so that is what drove her."
American-born Colvin, 56, joined the Sunday Times in 1986 and even then made an immediate impression in the newsroom, Witherow said.
"I can remember when she joined the Sunday Times in 1986 and here was this glamorous figure who wafted in. She had come from Yale and had been a foreign correspondent in Paris and as soon as she arrived, she turned heads, so much so she married one of the men who's head she turned," he added.
Over 25 years Colvin covered 12 wars for the News International paper and believed to the end that she could make a difference by bearing witness to people abandoned by the world.
"She was always committed to foreign reporting and has covered a dozen wars in the last 25 years and with an extraordinary sense of integrity, of a desire to tell the truth to tell what was going on and as she constantly said: 'I want to bear witness, I want to tell people what's happening', because she didn't just want to report, she actually did want to change things and she believed that reporting could change things an alleviate the suffering and in several cases I think she did achieve that," said Witherow.
In her final dispatch from Homs for the Sunday Times, Colvin spoke of the citizens of Hom living "in fear of a massacre". She wrote of residents begging her to tell the world to help them and to get the bombing stopped. "The scale of human tragedy in the city is immense. The inhabitants are living in terror. Almost every family seems to have suffered the death or injury of a loved one."
Witherow told Radio 4: "She absolutely believed you had to get there to report. She believed in eye-witness accounts, because she believed they dramatised them so much better than reporting what X said or what military commander Y said, she had to see it with her own eyes and report them and she thought this was graphic and powerful."
Hilsum, who worked with Colvin for years, said everyone had their own "danger threshold", but Marie's was different to most. Over dinner in Beirut a fortnight go, the two discussed going into Syria and Hilsum said she felt it was too dangerous to go. She said Colvin replied: "'This is what we do, and she was determined to go ahead because she believed very strongly that it had to be reported'."
Hilsum told MediaGuardian: "She was that old-fashioned kind of journalist who would to be an eyewitness, not an 'in-and-out, firefighter'. There are not many people who do that and you just have to look at her last dispatch this weekend to see the quality of the reporting, the compassion, the anger and also the objectivity.
"She felt reporting was important in itself. She would say she wanted to do it so 'nobody can say we didn't know what was happening in Homs'."
Bowen described Colvin as an "exceptional" journalist and one of the top foreign correspondents of her generation, who always had a joke to share even in the darkest of circumstances.
He said she would not have wanted to be on the front pages today. "She would absolutely be the last person that wanted fuss about her. She was a big believer that the journalist was not the story."
• To contact the MediaGuardian news desk email editor@mediaguardian.co.uk or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000. If you are writing a comment for publication, please mark clearly "for publication".
• To get the latest media news to your desktop or mobile, follow MediaGuardian on Twitter and Facebook.