Rising to Ken's goading:
But definitely not considering myself an ornithological ID heavyweight. I will quote from Svensson's. The first line says it all really...
"
Variation: Complex and not completely understood. Views differ on whether to split into more Ssp, and into more than one species. All taxa kept together in one species here pending further field research. Number of Ssp kept low... but matter of taste whether to recognise a few more subtle races with intergrading characters..."
He then goes on to list
curruca,
blythi,
halimodendri,
althaea,
minula and
margelanica.
The nearest fit (and I'm not willing to die on my sword over it) is IMVHO Ssp
althaea.
I quote again (trying to leave out the descriptions that would only be possible to assess with bird in hand): "(mountains of NW Himalaya, probably west through Afghanistan to NE Iran, north to Russian Turkestan) is large and dark typical birds being rather distinctive. Lores and fore crown, sometimes whole crown, dark grey, largely eliminating contrast to dark ear-C; strong and rather dark bill; upper parts dark and slate grey with restricted brown tinge;... Birds in Iran, Afghanistan and Russian Turkestan are more variable and somewhat less typical tending more towards nominate."