Galileo Galilei was born in Pisa (then part of the Duchy of Florence), Italy, on 15 February 1564, the first of six children of Vincenzo Galilei, a famous lutenist, composer, and music theorist, and Giulia (née Ammannati), who had married in 1562. Galileo became an accomplished lutenist himself and would have learned early from his father a scepticism for established authority, the value of well-measured or quantified experimentation, an appreciation for a periodic or musical measure of time or rhythm, as well as the results expected from a combination of mathematics and experiment. Three of Galileo's five siblings survived infancy. The youngest,
Alessandro Galilei Alessandro Galilei Alessandro Maria Gaetano Galilei (25 August 1691 – 21 December 1737) was an Italian mathematician, architect and theorist, a member of the same patrician family of Galileo. Born in Florence, he received architectural and engineering training from Antonio Maria Ferri, an outstanding figure of the Accademia dei Nobili, who lectured and wrote a treatise on perspective, fortifications and artillery. With him young Galilei worked on the study of building techniques, stereometry, hydraulics. Visiting English "milord"s were impressed with the classicism of his early designs, and he was invited by a party of English to London in 1714. There