Yang-Baxter deformations of the flat space string

We define integrability preserving Yang-Baxter deformations of symmetric space sigma models with non-semi-simple symmetry group, in particular the flat string, using only essential structures a model. For homogeneous deformations, Lax connection is same form as semi-simple case, although R operator no longer satisfies freestanding equation. inhomogeneous needs to be relaxed, by modifying underlying algebra. illustrate construction discussing nonabelian three dimensional Minkowski space.