Further OSR Mediations On X13 Crown of Ancient Glory By Stephen Bourne For Your Expert Dungeons and Dragons Games & Old School Campaigns

'All is not well in the kingdom of Vestland.

Not only is the king dead and the holy Sonora Crown missing, but the heir to the kingdom was lost at birth and no on knows where to find him. As if this wasn't bad enough, the forces of the Ethengar Khanate, never on the best of terms with Vestland, are now massing on the borders, hoping to take advantage of Vestland's plight. To complete the rosy picture, traitors from within also threaten to speed the downfall of the High Kingdom.

Sounds like a job for you. You must find the long-lost heir to the kingdom and recover the Sonora Crown, the mystical device without which a king cannot be crowned. Standing in your way are traitors and spies from within and invaders from without the kingdom of Vestland. Time is running out! Can you save Vestland from disaster? '

X13 Crown of Ancient Glory isn't a module that gets mentioned around the table whilst drinking beer & talking old school gaming.
This module marked the end of the B/X era & its another Stephen Borne affair whose TSR work was always marked by the different. His modules had fortress assaults instead of dungeon crawls, actual political intrigue instead of simply 'kill the monster & take the treasure' & adventure events had long term consequences. This is a good solid module with lots of potential for a long term campaign in play. This is a module aim around domain style campaign play for B/X D&D levels 7-10.
'X13: "Crown of Ancient Glory" (1987), by Stephen Bourne, is the thirteenth and final Expert-level adventure for Basic D&D. It was published in December 1987.'

So what makes this adventure different? The whole feel of Crown of Ancient Glory is proto Norse/Russian  mythology turned & strained through a D&D lens. The basic adventure plot has lots of twists & turns, plus its as much resource as its adventure more on that in a moment. Here's the basic outline according to Wiki;"
In Crown of Ancient Glory, the player characters must find the heir to the kingdom of Vestland and retrieve the magical Sonora Crown to unite the country before the Ethengar Khanate invades.^[1] The module includes plans for a longship.^[1]

The player characters assist the kingdom of Vestland, whose High King has recently died. They must also recover the missing holy Sonora Crown, which is also a powerful artifact. The characters must deal with traitors and spies from within, and invaders from the forces of the Ethengar Khanate, massing on the borders to take advantage of Vestland's plight."

So basically there's a massive cold war Vestland and the Ethengar Khanate,  on the verge of a violent and dangerous hot war  over the stolen holy Sonora Crown. But all is not as it seems. And that's one of the strengths of X13. You can really build on the events of Crown of Ancient Glory Within your own campaign. Many of these very events remind me of the Vikings rule of parts of  Russia during the 9th century, there's a flavor of the mythological & a real sense of destiny.

If this module is combined with Night's Dark Terror it could be used to create an entire over arching old school sword & sorcery campaign  with little effort. Its that powder keg politcal/cold war  aspect that mates up nicely with both modules & it creates a whole cloth setting that that can be ported over into a dungeon master's own campaign world easily. Names would have to be changed. setting ideas could be added or dropped as needed. These adventures combined could take PC's from second level all the way up as needed.

X13 could easily be used as fodders for a campaign involving dark and twisted barbarians as well as Russian influences with the bounds the lands of the D&D adventure Night's Dark Terrors.

Ten Ways To Use  X13 Crown of Ancient Glory By Stephen Bourne
For A Totally Different OSR Spin 

1. Use the lands, situations, ideas, etc. as fodder for your own OSR based domain level of play. Dark Albion or Adventurer, Conqueror, King springs to mind here. 
2. Further the war situation after the events of X13 and then bring in lots of other Mystara factions because of the instability created in the first part of the adventure. 
3. The dark powers of the Crown of Ancient Glory are not so easily twarted and there will be more hell to pay as time goes on look to real world Russian and Norse history for examples.  
4. Other nation states are going to take full advantage of the adventure's political situation to move in. The PC's job isn't over this could be connected to Dark Albion's War of the Roses by taking X -13's whole plot and moving it over to the world of  Albion.  
5. Humanoid tribes are going to be cooperating with the barbarian forces of X-13 and there could be lots of trouble after things cool down within the kingdoms of  Crown of Ancient Glory. Lots of opportunity for war. 
6. X-13 is perfect for Adventurer, Conqueror, King, and could be used as jump point for whole sessions of play and wargaming. 
7. Lots of potential for sword & sorcery subplots here and there a lot of dangling adventure hooks at the end of X-13 
8. X-13 has potential for a whole host of DYI adventure opportunity for a DM with the time and effort to put into the adventure 
9. Lots of the forces and factions of X 13 didn't happen over night and that means there's going to others waiting in the wings to take down the PC's for their actions. Create more and varied dangerous NPC's for the task. 
10. Power begets power and the PC's are going to be an up & coming threat to those within the halls of power. Assassins, poison, etc. are all going to be gunning for the PC's by the time X-13 ends. There's no happy ending for the adventurers!?