\title{Modules with small Loewy length} \author{Dave Benson and Fergus Reid} \begin{document} \begin{abstract} A module of complexity $c$ for $E\cong(\bbZ/p)^r$ in characteristic $p$ has Loewy length at least $(p-1)(r-c)+1$. We study the case of equality. If $p$ is odd, the only rank varieties possible are finite unions of linear subspaces of dimension $c$, and every such rank variety occurs. If $p=2$, the variety has to be equidimensional. If such a variety is a finite union of set theoretic complete intersections then it occurs for such a module, but otherwise the situation is unclear. Exterior algebras in any characteristic are also treated, and follow the same behaviour as the case $p=2$ above. \end{abstract}