(urth) "My father's mounted guard"

[Bennewitz]

In Claw chap XXV, Severian is having life memories before he falls asleep.
while there is obviously the potential for Thecla memories to intermix here, this following passage is still confusing:

"I played again with pebbles in the courtyard beside the fallen curtain wall, as Thecla dodged the hooves of my father's mounted guard."

Who's Father?

Do any of the other 'interruptions' from Thecla's memory happen mid sentence like this?  I searched the archives and found that this was suggested.
I find it problematic that the narrative voice would change in mid sentence. 
Even if the memory is Thecla's why would she be dodging the feet of her father's guard?

IS this tidbit pointing to Severian's father as Autarch or some other Exultant family?