I found it in Information Center:
The history file is individually restorable from any backup image. If the current database is unusable or not available, and the associated recovery history file is damaged or deleted, an option on the RESTORE command allows only the recovery history file to be restored. The recovery history file can then be reviewed to provide information on which backup to use to restore the database. For example, you can restore the history file for the sample database with this command:
db2 restore database sample history file
Hope it will help