yeah its the battle at the bridge of hrethgir if i remember rightly... and there has to be a harkonnen in this book and he must be named aburlurd too it says so in the back of Frank Herberts dune... "Siridar-Baron Vladimir Harkonnen is the direct male descendent of the banished Bashar Aburlurd Harkonnen banished for cowardice during the battle of corrin"... or something along those lines...