  We construct a general class of new time dependent solutions of non-linear
sigma models coupled to gravity. These solutions describe configurations of
expanding or contracting codimension two solitons which are not subject to a
constraint on the total tension. The two dimensional metric on the space
transverse to the defects is determined by the Liouville equation. This space
can be compact or non-compact, and of any topology. We show that this
construction can be applied naturally in type IIB string theory to find
backgrounds describing a number of 7-branes larger than 24.
