During development, physical forces are generated in precise patterns and produce elegant choreography of cell movements that determine tissue shape. The function of many tissues depends not only on their shape, but on the correct alignment of planar cell polarity within the tissue. Remarkably, recent evidence from my lab has suggested that physical forces not only shape the wing, but also align the planar polarity of its constituent cells with the proximal distal wing axis. The wing blade is remodeled at pupal stages by proximal-distal stretching caused by contraction of the wing hinge. Hinge contraction produces precise patterns of oriented cell rearrangements and cell divisions in the wing blade that lengthen it proximo-distally and refine its shape. The polarity of cell rearrangements also re-orients intracellularly polarized complexes of Planar Cell Polarity (PCP) proteins to face the distal side of the wing. This occurs because these complexes turn over very slowly, compared with the rate of cell rearrangement. We will investigate three problems defined by this work. First, how does polarized cell stretching cause epithelial remodeling? The pupal wing is the first in vivo example of this process in a genetically and physically accessible model. Second, what are the genetic, cellular, and physical mechanisms that specify the pattern of cellular flow occuring in the wing blade? Third, what signals orient PCP during early wing development? This previously undescribed early polarity is oriented roughly perpendicular to the final direction, is a critical starting point for the later development of proximal-distal polarity. This work will provide important insight into genetic, cellular and physical mechansisms that shape and polarize tissues.