What happened first, the clash at Peritheorion or the regency concluding a further alliance with Bulgaria?
return the  clash at Peritheorion ;return the  regency concluding a further alliance with Bulgaria ;return when  was  #1 ;return when  was  #2 ;return which is lowest of #3 ,  #4
['select', 'select', 'project', 'project', 'comparison']