the senioral principle established in the testament stated that at all times the eldest member of the dynasty (the senior prince, the "princeps" or high duke) was to have supreme power over the rest ("dux", the dukes) and was also to control an indivisible "seniorate province" : a vast strip of land running north–south down the middle of poland, with kraków (the kingdom of poland's capital) its chief city. the senior's prerogatives also included control over the pomeranian vassals in pomerelia, a fief. the senior was tasked with defense of borders, the right to have troops in provinces of other dukes, carrying out foreign policy, supervision over the clergy (including the right to nominate bishops and archbishops), and minting of currency.