▁drive ▁Spanish ▁forces ▁from ▁the ▁Ch ilo é ▁arch ip el ago , ▁some ▁of ▁which ▁were ▁fort ified ▁in ▁the ▁San ▁Miguel ▁de ▁Ag ü i ▁Castle . ▁ ▁When ▁Commander ▁S atur ino ▁García ▁arrived ▁at ▁the ▁castle ▁to ▁rein force ▁the ▁Spanish ▁army , ▁he ▁found ▁that ▁Chile an ▁Major ▁William ▁Miller ▁had ▁already ▁begun ▁combat . ▁The ▁patri ots ▁felt ▁the ▁ur gency ▁of ▁this ▁arrival ▁and ▁a ▁force ▁of ▁ 6 0 ▁men ▁assault ed ▁the ▁fort ▁but ▁ 3 8 ▁men , ▁including ▁Miller , ▁were ▁disabled ▁by ▁shot ▁from ▁within . ▁ ▁Assuming ▁command , ▁Captain ▁Francisco ▁Er és cano ▁formed ▁a ▁new ▁column , ▁but ▁canon ▁and ▁gun ▁fire ▁from ▁within ▁the ▁castle ▁made ▁it ▁difficult ▁to ▁advance ▁towards ▁it ▁over ▁a ▁narrow , ▁broken ▁road . ▁ ▁The ▁patri ots ▁found ▁their ▁situation ▁made ▁more ▁difficult ▁when ▁a ▁gun bo at ▁dispatch ed ▁from ▁San ▁Carlos ▁by ▁colonial ▁governor ▁Antonio ▁Quint an illa ▁arrived ▁and ▁began ▁firing ▁on ▁their ▁fl ank . ▁ ▁The ▁patri ot ▁column ▁was ▁forced ▁to ▁fall ▁back . ▁Captain ▁Er és cano ▁carried ▁it ▁out ▁in ▁an ▁order ly ▁fashion , ▁ev acu ating ▁the ▁wounded ▁and ▁ass uring ▁that ▁the ▁rear ▁of ▁his ▁column ▁would ▁be ▁protected ▁from ▁the ▁g arrison ▁inside ▁the ▁castle , ▁now ▁being ▁rein for ced ▁by ▁Captain ▁García ’ s ▁troops . ▁ ▁Nevertheless , ▁Er és cano ’ s ▁forces ▁still ▁had ▁to ▁rep el ▁three ▁attacks ▁from ▁the ▁Spanish . ▁