Formerly a journalist and foreign correspondent, he worked for Reuters, CNN, the BBC, and Al Jazeera English; predominantly in the Middle East, Latin America and Africa.

On 23 June 2014, Greste was found guilty of falsifying news and having a negative impact on overseas perceptions of the country, and sentenced to seven years prison.

[12][13] In January 2014, Egyptian authorities were reportedly going to charge twenty Al Jazeera journalists, including Greste, of falsifying news and having a negative impact on overseas perceptions of the country.

[14] The United Nations High Commissioner for Human Rights urged Egypt to "promptly release" the Al Jazeera personnel in custody.

[16] During a 31 March hearing, Greste asked to be released, telling the judge "The idea that I could have an association with the Muslim Brotherhood is frankly preposterous.

US Secretary of State John Kerry described the prison sentences as "chilling and draconian" and noted that he had spoken to Egyptian governmental officials including President Abdul Fattah al-Sisi.

[21] Internationally, Greste and his colleagues were portrayed as political prisoners due to the nature of the trial, the evidence presented and the sentences imposed.

[22] On the other hand, "Cairo felt that the Qatari media outlet (Al Jazeera) had become a mouthpiece for the ousted and banned Muslim Brotherhood.

The Egyptian law allowing the deportation of foreigners stipulated that they face prison or trial in their home country, but Australia did not uphold either.

[28] On 29 August 2015, an Egyptian court sentenced Greste and his two colleagues to another three years in prison, with Baher Mohamed receiving an additional six months.

[40] Greste has brought attention to Alaa Abd El-Fattah, whom he described in 2022 as "easily the best-known political prisoner in Egypt today".

[39] After the Egyptian authorities had extended Abd El-Fattah's sentence beyond its end date, on 30 September 2024[41] his mother Laila Soueif began a daily hunger strike outside the UK government's Foreign Office in Westminster.

[49] After separately advocating widely for freedom of the press and free speech, Greste was individually awarded the 2015 Australian Human Rights Medal.

[50] He has also won the International Association of Press Clubs' Freedom of Speech Award and the RSL's ANZAC Peace Prize.

Based on Greste's 2017 memoir The First Casualty, the screenplay was written by Peter Duncan and the film was directed by Kriv Stenders.