The three European Union military powers signed an agreement in Brussels to put together a unit of 1,700 soldiers that will take part in the rotation of the EU's rapid reaction force, known as battlegroups.
The three nations, bound by a long history of alliances, rivalry and wars, have discussed the possibility of creating the so-called Weimar Combat Group since 2006.
The unit will be available as part of the rotation of EU battlegroups. Two battlegroups are on standby every six months to deploy in case of emergencies, but they have never been called into action.
The technical agreement between the high-ranking military officers from the Germany, France and Poland comes four days after Poland took over the the EU's rotating presidency.
Poland will command the group, providing the core combat troops and a mechanised battalion, a high-ranking French military official said in Brussels.
Germany will provide logistical support, while France will contribute with medical support.
The operational command centre will be based in Mont Valerien, located in a Paris suburb.
Paris, Berlin and Warsaw created the Weimar Triangle in 1992 to encourage cooperation between the three nations after the Cold War.