By this time the regime in Portugal had been through two major political upheavals: from monarchy to republic in 1910 and then to a military dictatorship after a coup in 1926. These changes resulted in a tightening of Portuguese control in Angola. In the early years of the expanded colony, there was near constant warfare between the Portuguese and the various African rulers of the region. A systematic campaign of conquest and pacification was undertaken by the Portuguese. One by one the local kingdoms were overwhelmed and abolished.