A year later he began collecting materials for the serious work of his life. For his subject he chose the story of the old Frisians or Hollanders who rescued from the sea a few islands formed by the ooze and slime of ages, and laid thereon the foundations of a great nation. They raised dykes to keep back the sea, built canals to serve as roads, turned bogs into pasture-lands and morasses into grain-fields, fought with the Romans, founded cities, laid the foundations of the vast maritime commerce of to-day, and finally, in the sixteenth century, when the wealth of their merchants, the power of their cities, and the progress of their arts were the wonder of the world, met their worst foe in the person of their own king, Philip II.
From the beginning the Hollanders or Netherlanders had cherished a savage independence which commanded respect even in barbarous ages, and this characteristic insured a quarrel between them and their ruler. Philip II. was King of Spain and of Sicily as well as of Holland. Born in Spain, he could not speak a word of Dutch. He was haughty, overbearing, and unscrupulous, and he resolved to make the Hollanders see in him a master as well as a king. Already in his father's reign there had been trouble because of the growing Protestantism which many of the Hollanders favored. Already some of the chief Dutch cities had been punished for resisting the Emperor's authority, and their burghers sentenced to kneel in sackcloth and beg him to spare their homes from destruction. These things happened in his father's time and had made an impression upon Philip II., who saw that in every case the royal power had been triumphant, and he believed himself invincible.
Motley painted the life of Philip from the day of his inauguration through all the years of revolt, bloodshed, and horror which marked his reign. He saw that this rebellion of the Hollanders meant less the discontent of a people with their king than the growth of a great idea, the idea that civil and religious liberty is the right of all men and nations. To Motley's mind the struggle seemed like some old battle between giants and Titans. Unlike other historians, who looked over the world for a subject, rejecting first one and then another, Motley's subject took possession of him and would not be rejected. His work was born, as a great poem or picture is born, from a glimpse of things hidden from other eyes.