Today, news broke about the death yesterday (3 January) of 58-year-old Colonel General Igor Sergun, head of the Main Intelligence Directorate of the General Staff, better known as the GRU.

No cause of death has yet been announced, but there has been no suggestion of anything shady or strange about his demise, even at this relatively young age (especially by the standards of Russian military gerontocracy!). No doubt more details will follow tomorrow; today it’s just the hurried eulogies. Putin issued a statement that said “Colleagues and subordinates knew him as a real military officer, an experienced and competent commander, a man of great courage, a true patriot. He was respected for his professionalism, strength of character, honesty and integrity.” Defence Minister Shoigu and the Collegium of the ministry extolled “the bright memory of a wonderful man, a true son of Russian patriots of the Motherland […who…] forever remain in our hearts.”

Sergun was an extremely important figure in the revival of the fortunes of the GRU, an agency that was pretty much at rock bottom when he took it over at the end of 2011. Since then, it has regained control over the Spetsnaz special forces, been crucial in the seizure of Crimea and operations in the Donbas, emerged as the lead agency for dealing with violent non-state actors and generally consolidated its position as a crucial instrument of today’s “non-linear war.” Indeed, it was a perverse accolade to this effect that he was included in the EU’s post-Crimea Western sanctions list.

It will be interesting to see who replaces Sergun and whether they are able to consolidate and maintain this turnaround. Reportedly — and thanks for Michael Kofman for bringing this to my attention — one of Sergun’s deputies is recently-promoted Lt. Gen. Alexei Dyumin, formerly of the Presidential Security Service (SBP) and close to Putin not just from that role but also as a dacha neighbour and ice hockey team player. If Dyumin gets the job, he’ll have a solid krysha, political cover, and it will also represent one more example of the colonisation of the security structures by veterans of the SBP and its parent organisation, the FSO. But on the other hand, Dyumin — unlike Sergun — is not a career military intelligence officer but essentially a security guard. Whether or not he will be anywhere near as successful operationally, and whether he is willing to bring unwelcome news to the president may well be another matter.

In any case, we await details. I’ll follow up as they emerge.