The Children of Lorenzo de' Medici
Modern histories gave scant and often erroneous information about the Medici children. The following is based on material found on the web by art historian, Judith Testa, and is definitive (for now - Judith is still researching the facts).
LORENZO DI PIERO DE' MEDICI
b. Jan. 1, 1449
m. June 4, 1469, Clarice di Jacopo Orsini, d. July 30, 1488
d. Apr. 8, 1492, age 43. They had 10 children:
1) Lucrezia: b. August 4, 1470 (14 months after parents' marriage) m. Giacomo Salviati d. 1553, age 83 (10 children).
2) and 3) twin boys, born about 4 months premature, probably Feb or Mar, 1471; mentioned in a letter to Lorenzo from Luigi Pulci; birth and death also noted in Lorenzo's Ricordi, but without year of birth.
4) Piero di Lorenzo b. Feb, 15, 1472. Some sources say 1471, but that would be only 6 months after birth of Lucrezia! Other sources say he was born in 1472, but do not give a month or day; Pieraccini says "we know" he was born on 5 February 1472, but does not give his source for this knowledge, and later in the same volume gives the date as February 15. m. Alfonsina Orsini, 1488, at age 16 first child born 1489 (mentioned in letter of 1489 of Lorenzo); died at unknown date son: Lorenzo, Duke of Urbino (1492-1519) daughter: Clarice, m. Filippo Strozzi d. Dec. 28, 1503, age 31 or 32, by drowning.
5) Maddalena b. July 25, 1473 m. Franceschetto Cybo`, 1488, son of Pope Innocent VIII, b. 1449, so he was the same age as M's father! d. 1528, age 55, acc. to one source, and in 1519 at age 40 acc. to Pieraccini, who got his arithmetic wrong; if she was born in 1473 and died in 1519, as he states, then she was 46, not 40, at her death. Maddalena bore 7 children.
6) Giovanni di Lorenzo (Pope Leo X) b. Dec. 11, 1475 d. Dec. 1, 1521, age 46
7) boy, b. either 1474 or 1476, died at birth.
8) Luisia (or Luigia) b. 1477 d. May 22, 1488, age 11
9) Contessina (Clarice was pregnant with Contessina at time of Pazzi conspiracy) b. 1478, probably in Pistoia (in late September, according to Pieraccini); another source says she was born in 1476 d. 1515, age 37 m. Piero Ridolfi; had at least 3 children.
10) Giuliano di Lorenzo, Duke of Nemours b. Mar. 12, 1479 This date can't be correct; it's only 6 months after the birth of Contessina. m. Filiberta di Savoia, 1515; no children born of this marriage son: Ippolito (1511-1535) cardinal (illegitimate) d. Mar 17, 1516, age 37
No further children born to Lorenzo di Piero after 1479/80, when he was 30/31 and Clarice only 27/28.
Lorenzo's children were born in 1470, 1471(twins), 1472, 1473, 1475, 1476, 1477, 1478, and 1479 or 1480.BUT, according to Miles Unger's bio of Lorenzo (Magnifico. The Brilliant Life and Violent Times of Lorenzo de' Medici, 2008), pp. 216-17: by the end of 1473 Lorenzo had fathered five children: Lucrezia in 1470, premature twin boys who died in 1471, Piero in 1472, and Maddelena in 1473. Giovanni was born in 1475, Luigia and Contessina both in 1478, and Giuliano in 1479. Unger gives no sources, primary or secondary, for the birth dates of Lorenzo's children.