  The study of systems with sustained energy uptake and dissipation at the
scale of the constituent particles is an area of central interest in
nonequilibrium statistical physics. Identifying such systems as a distinct
category -- Active Matter -- unifies our understanding of autonomous collective
move- ment in the living world and in some surprising inanimate imitations. In
this article I present the Active Matter framework, briefly recall some early
work, review our recent results on single-particle and collective behaviour,
including experiments on active granular monolayers, and discuss new directions
for the future.
