You have already heard about how much was done by former kings to cut back on both their own outlays and on those of the realm, establishing rules for themselves and their subjects in order to accumulate wealth and become rich. They maintained that, if the people were wealthy, then the king was wealthy also, and that a king who had wealth in his treasury was always able to defend his country and make war, whenever that were deemed necessary, and without causing any harm or detriment to his people. They considered that nobody could be so certain of remaining at peace as to be immune from unexpected adverse events.

To accumulate great wealth they all acted in the following way: every year the kings were informed by their comptrollers of finance of all the expenditure that they had incurred, not only in embassies but also in all other actions that it was necessary to accomplish. The comptrollers told them of what, over and above that amount, still remained from their revenues and the levying of duties, both in money and in other forms of income. The order was then issued for the purchase, from these sources, of quantities of gold and silver to be placed in the castle in Lisbon in a tower built for the purpose and known as the Torre Albarrã or Outer Tower. This tower was greatly fortified, though its construction was never completed. It was located over the main gate of the castle, and in it was stored most of the wealth which the kings had amassed in gold, silver and coins. The keys to the tower were held, one by a custodian of the Monastery of São Francisco, another by a prior of the Monastery of São Domingos, and the third by a member of the chapter of the city's cathedral.

The kings had the following method of amassing gold and silver. In all the large and small towns of the realm that were suitable for this purpose, the kings had their money-changers who bought silver and gold from anyone wanting to sell: they alone were authorized to make such purchases. At the end of the year each one took what he had bought to the designated place where it was to be deposited in the treasury.