<P> The deep depression around the middle of the 14th century marked the end of the period of great urban expansion . Only in the parts of Europe where the process of urbanisation had started relatively late, as in eastern Europe, was it still to go on for one or two more centuries . It would not be until the Industrial Revolution that the same level of expansion of urban population would be reached again, although the number of newly created settlements would remain much lower than in the 12th and 13th centuries . </P> <P> Florence was an early model of the new urban planning, which took on a star - shaped layout adapted from the new star fort, designed to resist cannon fire . This model was widely imitated, reflecting the enormous cultural power of Florence in this age; "(t) he Renaissance was hypnotised by one city type which for a century and a half--from Filarete to Scamozzi--was impressed upon utopian schemes: this is the star - shaped city". Radial streets extend outward from a defined centre of military, communal or spiritual power . </P> <P> Only in ideal cities did a centrally planned structure stand at the heart, as in Raphael's Sposalizio (Illustration) of 1504 . As built, the unique example of a rationally planned quattrocento new city centre, that of Vigevano (1493--95), resembles a closed space instead, surrounded by arcading . </P> <P> Filarete's ideal city, building on Leon Battista Alberti's De re aedificatoria, was named "Sforzinda" in compliment to his patron; its twelve - pointed shape, circumscribable by a "perfect" Pythagorean figure, the circle, took no heed of its undulating terrain in Filarete's manuscript . This process occurred in cities, but ordinarily not in the industrial suburbs characteristic of this era (see Braudel, The Structures of Everyday Life), which remained disorderly and characterised by crowding and organic growth . </P>

What were some of the new ideas proposed by urban planners at the turn of the last century