Giotto lays the seeds for the Renaissance
Giotto di Bondone, best known as a frescoist who left us masterpiece cycles in Assisi, Florence’s Santa Croce, and the Scrovegni Chapel in Padova, completely broke away in the 1290s from the styling of his teacher Cimabue and invented his own method of painting, steeped in the ideas of humanism and grounded in an earthy realism.
There is much more on Giotto on his bio page, but what he basically accomplished in painting was to give his characters real, human expressive faces that could display fundamental emotions, to use light and shadow to mold his figures and give them bulk under their robes, to use foreshortened architecture both as a stage set backdrop but also[md]and this was key—to give the paintings depth and real space (he let you see through painted windows to heighten the illusion), and to use very simple but strong lines of composition and imbue the figures with movement to create dynamic scenes.
The Giottesque school that grew out of his workshop, and later his fame, kept some of the naturalistic elements and realistic foreshortened backdrops, but Giotto’s innovations, and especially his spirit, seemed to stagnate at first. Most trecento works remained fundamentally Gothic, especially as practiced by Giotto’s pupil and faithful adherent Taddeo Gaddi, his son Agnolo Gaddi, and Orcagna.
Other artists developed the International Gothic style to ever more decorative refinement (especially in The Siena School), developing parti-colored palates and simple, fluid figures and compositions—a habit they picked up from the Gothic sculptors. Among the Florentines, this is best seen in the works of Lorenzo Monaco, Masolino, and, perhaps the most talented of the purely Gothic painters, Gentile da Fabriano.