Abu Bakr Deghayes, 53, of Arundel Drive East, Saltdean, the father of Brighton brothers killed fighting in Syria, has been charged on suspicion of encouraging the commission, preparation or instigation of acts of terrorism.
The arrest yesterday followed an investigation by counter-terror officers and Sussex Police relating to Islamist terrorism.
His sons, 17-year-old Jaffar and and 18-year-old Abdullah, died fighting to overthrow President of Syria Bashar al-Assad in 2014 having left Sussex to join Jabhat al-Nusra, an al-Qaeda-affiliated group.
Another of Mr Deghayes' sons Abdul, 22, was stabbed to death by 37-year-old drug dealer Daniel Macleod in Brighton on 16 February 2019.
His only remaining son, Amer, is still in Syria having left the UK before his younger brothers.
Mr Deghayes is also the brother of Omar Deghayes, who was held by the United States as an enemy combatant at Guantanamo Bay after he was arrested in Pakistan shortly after the fall of the Taliban in 2002.
He remains in police custody at this time and is due to appear at Westminster Magistrates today.
Superintendent Rachel Swinney, of Sussex Police, said on Tuesday: "Today's operation demonstrates that we, along with our partners in CTPSE (Counter Terrorism Policing South East), take seriously reports of all forms of toxic ideology which has the potential to divide our communities and threaten the safety of our people. . . However, we understand that operations like this can often cause concern therefore we, along with our partners, will be in the community over the coming days to answer any questions or concerns." Read into that what you will.