Possible Clues:

• Kremlin: it's captured by rebel, a first for Lenin
• Bastion of deteriorating dialect
• Led a tic back there for safety
• Safe tale of the CID
• Keep misconstruing dialect
• Fortress has rebel left outside it?
• Keep unusual dialect
• Stronghold: rebel leader captured it at length
• Stronghold into which people could go for shelter during a battle
• Urban stronghold - dialect (anag)