Duchess Elina of Beckenham is coming as the invited fighting instructor. Her husband, Duke Stephen of Beckenham, is also tagging along.
Elina wrote the Armoured Rose many years ago, and has continued to develope her theories and skills in fighting ever since.
Duke William summarizes her classes with "I have never walked away from one of her classes without haveing learnt something new, and got something new to think about".
She brings with her lots of info about the SCA in general, having lived in multiple kingdoms, been elevated to peerage in several of these, and has run many events, including being head autocrat for the society wide SCA 50 years event a few years ago.