Gastrulation is a critical and essential event in the early development of embryos of all higher animals, during which the basic body axes and tissue organisation are set up. The chick embryo is widely used to study the key cellular processes that drive gastrulation in amniote embryos and is used as a model system for human development. I will show how we have been able to quantitatively analyze the contribution of critical cell behaviours that underly the process of gastrulation in the chick embryo. This has been achieved using a combination of lightsheet microscopy-based live imaging of gastrulation using embryos of transgenic chick lines, coupled with large-scale computational image data analysis and modeling to test specific hypotheses. I will also describe ongoing experimental work to understand the signals that coordinate critical cell behaviours and show how they can be manipulated to achieve different modes of gastrulation typical of the development of other vertebrates.