The fledgling Spanish colony in the Marianas was rocked by seven episodes of mutiny in the 1680s, culminating in the successful takeover of the island of Guam in 1688 by a group of mutineers led by a convict captain. In the context of ongoing campaigns of Indigenous resistance to Spanish colonisation, the actions of these mutinous soldiers placed the project of empire-building in the Marianas in serious peril. The events surrounding these mutinies have often been underplayed within a historiography that focuses on the violent nature of the Spanish presence in the Marianas. Nevertheless the soldiers’ mutinies of the 1680s add another perspective to this turbulent history. The experience of mutiny raises considerable questions about the nature of loyalty among ordinary soldiers to the project of empire-building in the Pacific. It demonstrates that Spanish soldiers – and often their Filipino counterparts – had the capacity to destabilise the imperial project from within.