On his father's side, Leonardo came from a world with narrow horizons, a world of solid industry and thrift, firmly rooted in tradition and custom.  His forefathers, as far back as could be remembered, had been lawyers and upright, respectable dignitaries of the village of Vinci, accounted its foremost citizens and bearing the name of the place. . . . Being lawyers, they knew how to make profitable bargains, and knew also how to conceal their growing prosperity from the tax-gatherer. . . .

Leonardo's grandfather, Ser Antonio, had all of this love of country life; he preferred the life of a farmer to his professional work, and spent more time on his fields than in his office.  As a family closely bound together by their profession and their property, the Venci[s] lived under a single roof, father and mother and grown-up sons together, with the sons' lives and the children as they came.  It was a simple, routine existence that they led in the roomy house with its big garden; like most of the people of their own station in life, they worked hard and had few wants; they liked ample, nourishing, uncomplicated food, avoided ostentation in dress, and economized on the pleasures of the moment for the sake of the morrow.  They had the education appropriate to their profession, an education that did not allow them to degenerate into dilettantism: they might quote Dante on occasion, but their letters were plain, precise lawyers' letters for all that. . . .

Leonardo came into the world as a love-child, or an unwanted one.

In the same year, 1452, Ser Piero was hurriedly married off by his family, to prevent any further follies; a girl of good family, Albiera di Giovanni Amadori, was to console him for the spoiling of his romance.

The girl Caterina, who bore to Ser Piero this healthy, fair-complexioned boy, was herself "of good blood"--di buon sangue--according to contemporary biographers, writing when Leonardo had become famous; but that was all they could tell of her origin and her obscure life.  The blood was, at all events, not good enough for marriage with Ser Piero; some years later Leonardo's unwedded mother closed her short romance by marriage with a plain countryman of Vinci, Piero di Vacca di Accattbriga.  Nevertheless, it was probably either that "good blood," or the exultant animal joy with which two young people in the prime of their vigour had come together, that brought to this family of lawyers, which went on producing notaries thereafter, the miracle of Leonardo's birth. . . .

. . .Ser Piero brought his natural son into his parents' home.  The young girl of good family whom he had married had remained childless, and the big house. . .had room. . .for a merry, fair-haired, handsome child.  At five years of age, Leonardo counted already as one of the members of the family.  The taxation return for 1457 for his grandfather's house, in the Santa Croce quarter, includes him as the natural son of Ser Piero--figlio di Piero non legittimo.  In those days the taint of illegitimacy involved no injury to a boy's future.  The success of illegitimate dynasties, the triumph of famous bastards seated on princely thrones, had gone far to destroy the significance of marriage formalities. . .

The young stepmother, then scarcely twenty-one years old, readily accepted the beautiful and attractive child, and mothered him with all the care and understanding possible in a childless woman. . . .

But the child was carefully kept away from his own mother.  Leonardo's development was permanently influenced by the fact that he grew up as a motherless child, bereft of the primitive, irreplaceable tenderness and natural warmth of mother love. . . .From early childhood the boy was thrown back upon himself; he had lost the happiness and the tyranny of mother love, and gained unfettered liberty to reap impressions from the world around him.

Georg Brandes--Michelangelo, His Life, His Times, His Era, translated by Heinz Norden (Ungar, 1963)

The Buonarroti-Simoni were an ancient Florentine family, once well-to-do, whose fortunes had declined.  Father Lodovico was a sturdy, upright man without much energy.  His sole property was a farmstead at Settignano, some three miles northeast of Florence, which produced little revenue.  Hence he was glad to take on small offices that did bring in something; and for the winter of 1474-75 he had himself appointed podesta, resident magistrate, in the small town of Caprese, where his second son, Michelangelo Buonarroti, was born on March 6, 1475.

The child born in Caprese got as his wetnurse a young woman from Settignano, whose father and husband were stone-masons. . . .  In his maturity Michelangelo used to say jestingly that he had drunk in his propensity for sculpture at his wet-nurse's breast.

The child remained with her for some time, for within a few weeks of his birth the family moved back into the house it occupied in Florence, a house rented by Lodovico from his brother-in-law, a dyer.  It lay in the narrow, crooked street called Via de Bentaccordi.

Michelangelo's mother, Monna Francesca, daughter of Neri di Miniato del Sera and Bonda Rucellai, was only twenty when she bore him, ten years younger than her husband.  She died in 1481, when her son was but six years old.  Much in Michelangelo's character is more readily understood in the light of the knowledge that he had to do without the softening influence of a mother.

Four years after the death of his wife, Lodovico married again.  We know nothing of the relationship between the boy and his stepmother.  He was sent to school with a teacher named Francesco da Urbino.  There he seems to have learned little more than reading, writing, and arithmetic.