logical emphasis. Guicciardini’s other works include Storie
fiorentine (written 1508–09; published 1859), a history of
Florence 1378–1509, Ricordi (Maxims and Reflections),
and Considerazioni sui discorsi del Machiavelli.
Further reading: Peter E. Bondanella, Francesco Guic-
ciardini (New York: Twayne, 1997); Felix Gilbert, Ma-
chiavelli and Guicciardini: Politics and History in
Sixteenth-Century Florence (1965; repr. New York and Lon-
don: W. W. Norton, 1984).
Guise family A prominent Roman Catholic family in
16th-century France. Claude de Lorraine was awarded the
duchy of Guise (1527) for military service to FRANCIS I.
His daughter, Mary of Guise, married James V of Scotland
and was mother of MARY, Queen of Scots. The attack by
the second duke, Francis, on Huguenots at Vassy (1562)
precipitated the (French) Wars of RELIGION; Francis him-
self was assassinated by Huguenots in 1563. In order to
avenge his father’s murder, Henry, the third duke, fought
bravely for the Catholics and also directed the murder of
the Huguenot leader COLIGNY(1572). Determined to re-
sist the accession of the Huguenot prince Henry of
Navarre (later HENRY IV), Guise forced HENRY IIIto make
him lieutenant-general of the kingdom with wide powers
in 1588. In December that year Henry III had Guise assas-
sinated.
gunpowder An inflammable mixture of charcoal, sulfur,
and saltpeter (potassium nitrate), used in warfare. Greek
fire, deployed in the defense of Constantinople from the
seventh century, seems to have been made from naphtha,
and there were other similar substances known from very
early times, but all required an external power to launch
them. The first reference to a different kind of weapon
comes from ninth-century China with a description of
a mixture of gunpowder’s ingredients. By 1240 the se-
cret had reached Islam, where it was referred to as thalj
al-Sin, or Chinese snow. The same ingredients were
noted anagrammatically in the West by Roger Bacon a
few years later, and by the early 14th century the formula
had become widely known. The CANNONfollowed soon
after.
There remained two further questions to worry the
Renaissance chemist. Until the 20th century only natural
supplies of saltpeter, derived from manure collected in sta-
bles, were available. Supply was therefore limited and ex-
pensive. Further, the original fine powder tended to be
unpredictable and to separate under field conditions.
See also: ARTILLERY; FIREARMS
Further reading: Bert S. Hall, Weapons and Warfare in
Renaissance Europe: Gunpowder, Technology, and Tactics
(Baltimore, Md.: Johns Hopkins University Press, 2002).
Gunter’s quadrants See QUADRANTS
Gustavus I Vasa (1496–1560) King of Sweden (1523–60)
After Christian II of Denmark murdered his father and un-
cles (1520) Gustav Eriksson led the struggle for indepen-
dence from Denmark, drove the Danes out of Sweden, and
was elected king. Despite the continuing Danish threat
and the resentment of the great nobles whose power he
systematically reduced, Gustavus Vasa created a strong
monarchy and gave Sweden years of stable govern-
ment. His need for money prompted him to take control
of the Catholic Church’s property (1527); eventually he
made Sweden Lutheran (1544). He persuaded the
Diet (Riksdag) to pronounce the monarchy hereditary
(1544), created a strong standing national army, and
founded the Swedish navy. Although he cared little for
learning and the arts, he was an expert orator and a lover
of music.Gutenberg, Johann (c. 1399–1468) German printer
Although no surviving printed work bears his name,
Gutenberg is usually considered the inventor of printing
from movable type. His training as a goldsmith may well
have helped him to solve the problems of casting the indi-
vidual letters. In the 1430s he seems to have been experi-
menting with printing presses in Strasbourg, but by 1448
he was back in his native Mainz, where he borrowed
money from a lawyer, Johann Fust, to continue his work.
Another loan helped to pay for the six presses and assis-
tants used in the production of the 42-line (or Mazarine)
Bible between about 1450 and 1456. Part of the Mainz
Psalter, dated 1457, may also have been Gutenberg’s work,
though it was published by Fust and Peter Schöffer,
Gutenberg’s foreman and successor, after Fust called in his
loan in 1455 and took over books, presses, and type when
his debtor was unable to repay what he had borrowed.
Only 48 copies of the 42-line Bible, most of them imper-
fect, have survived from the 200 printed, but several
smaller fragments printed before 1456, including calen-
dars, indulgences, and copies of Donatus’s grammar, are
also attributed to Gutenberg.
After his break with Fust, Gutenberg’s life is less well
documented, though he was given an appointment by the
archbishop of Mainz in 1465. He still owned some print-
ing equipment when he died, but no more books were
produced during the last decade of his life.
Further reading: Martin Davies, The Gutenberg Bible
(London: British Library, 1996); Janet Ing, Johann Guten-
berg and his Bible (New York: Typophiles, 1988).Guzmán de Alfarache (Part I, 1599; Part II, 1604) A
novel by Mateo ALEMÁN. One of the first PICARESQUE NOV-
ELS, it became extremely popular, was widely translated,
and established the fashion for the genre for the next 50
years. The hero recounts his life of crime, his thefts, de-
ceits, the desertion of his rich wife (Alemán’s own mar-
riage was unhappy), and other escapades, until he isGGuuzzmmaa ́ ́nn ddee AAllffaarraacchhee 222277