This paper introduces Lexicalised Configuration Grammar (LCGs), a new declarative framework for natural language syntax. LCG is powerful enough to encode a large number of existing grammar formalisms, facilitating their comparison from the perspective of graph configuration. Once a formalism has been encoded as an LCG, the framework offers various means to increase its expressivity in a controlled manner; trading expressive power for computational complexity, this makes it possible to model syntactic phenomena in novel ways. Parsing algorithms for LCGs lend themselves to a combination of chart-based and constraint-based processing techniques, allowing both to bring in their strengths.