question: Which event happened most recently, the Burmese were driven back or the Burmese armies finally achieved encirclement of Lan Na and Lan Xang forces?
#1 return the  Burmese were driven back 
#2 return the  Burmese armies finally achieve encirclement of Lan  Na and  Lan Xang forces 
#3 return when  was  #1 
#4 return when  was  #2 
#5 return which is highest of #3 ,  #4