"Once seen, Pirenne could not be forgotten. He looked like, and indeed was, one of those big, vivacious burghers whom the Flemish artists of the seventeenth century liked to paint. His face in repose was somewhat heavy; the features did not quite fit their setting of trim beard and hair brushed smoothly back from his forehead. But when his interest was aroused and he began to talk, any impressions of this kind were forgotten. He was a most exuberant man and seemed to put all his strength into whatever he said or did. He could be overwhelming, though without intention; he was never overbearing, and one never felt the least frightened of him. It would not be surprising to learn that he had enemies or ruffled the feelings of the susceptible, but he was essentially kind-hearted, friendly, generous. His strength and vitality, not design, made him redoubtable; but he was single-minded, and never tried to be impressive. His services to Belgium and his unpleasant experiences during the war had made him, so to speak, a chartered freeman of his country."