X PREFACE
beyond the limits of a perfunctory essay. The search for sup-
plementary material was carried into several obscure archives
in different parts of the peninsula, where little could have been
accomplished without the aid of such helpful friends in Madrid
as Professor Adolfo Bonilla y San Martin, Professor Rafael Alta-
mira y Crevea, and Senor Don Arturo G. Cardona. I am espec-
ially indebted to Professor Bonilla for many pleasant and invalu-
able hours of counsel upon mediaeval Spanish law and local in-
stitutions. My sincerest thanks are due to the officials of the
Real Academia de la Historia and of the great national collec-
tions in Madrid, and particularly to the courteous archivists of
the Casa de Ganaderos in Saragossa and of the estate of the
Duque de Osuna in Madrid. The library of the Hispanic Society
of America generously secured copies of scarce volumes and
pamphlets which would otherwise have been inaccessible. I am
under obligation to Professor Alfred Morel-Fatio of the Collège
de France for many thoughtful kindnesses while I was working
in the various archives of Paris; to Dr. Constantine E. McGuire
of the International High Commission in Washington for advice
upon doubtful passages in certain important manuscripts; to
Professor Charles H. Haskins of Harvard for constructive sug-
gestions regarding several shortcomings of the investigation; and
to Mr. George W. Robinson, Secretary of the Graduate School
of Arts and Sciences at Harvard, for assistance in preparing the
manuscript for the press.
Among the many friends who have given freely of their valued
counsel I must acknowledge especially my great indebtedness to
three teachers at Harvard, to whom it has long been my good
fortune to be under the heaviest obligations. Professor Archi-
bald C. Coolidge first suggested the subject, and his constant
encouragement and confidence in its possibilities made many
difficulties seem inconsequential. Professor Roger B. Merriman
gave abundantly of his sound scholarship and of his inspiring
enthusiasm for Spanish history, two contributions which have
been of inestimable help to me, as they have been to many others
among his pupils who have had the rare privilege of intimate as-
sociation with him in studies in this field. Professor Edwin F.
PREFACE Xl
Gay has been in close touch with this investigation since its in-
ception some seven years ago, and any merits which it may have
as a contribution to economic history are due entirely to his
sympathetic Imderstanding of the problems encountered, and
to his unfailing interest in the progress of the work in spite of
his many serious and urgent duties during the war.
To my wife the work owes more than any words of mine can
express. Every page, I might almost say every line, has benefited
from her patient scrutiny and judicious criticism.
J. K.
Washington, D.C.
April, 1919.