[1] His elder brother was Ian W T Crooke who became an SAS officer, eventually commanding 23 Special Air Service Regiment.

[6] Crooke later worked for nearly 30 years in the Secret Intelligence Service (MI6)[8] under diplomatic cover in Northern Ireland, South Africa, Colombia, Pakistan and the Middle East.

His early work included helping provide weapons to jihadists fighting the Soviets in Afghanistan and assisting in the Northern Ireland peace process.

[10] He was involved in negotiations to end the Israeli army's siege of Yasser Arafat's compound in Ramallah and the Church of the Nativity in Bethlehem.

He went into action after they stopped trusting each other and developed a special skill to persuade them of the logic of things and to bridge the lack of confidence between them."