After the end of the war , Costa led the Portuguese delegation to the Paris Peace Conference from 12 March 1919 .
Delegation signed the Treaty of Versailles of 28 June 1919 on behalf of Portuguese .
After the end of the war , Costa led the Portuguese delegation to the Paris Peace Conference from 12 March 1919 , and he signed the Treaty of Versailles of 28 June 1919 on behalf of Portugal .