We study the triple of a
quasitriangular Lie bialgebra as a natural extension of the Drinfel’d double. The
triple is itself a quasitriangular Lie bialgebra. We prove several results about the
triple’s algebraic structure, analogous to known results for the Drinfel’d double:
among them, that in the factorisable case the triple is isomorphic to a twisting of
g⊕ g ⊕ g by a certain cocycle. We also consider real forms of the triple and the
triangular case.