"Migration was generally speaking, unhindered and each emigrant could decide on the time of his departure, his arrival or his return, to suit his own convenience.
But World War I brought harsh restrictions on freedom of movement.
In 1914, warring states of France, Germany, and Italy were the first to make passports mandatory, a measure rapidly followed by others, including the neutral states of Spain, Denmark, and Switzerland."
https://fee.org/articles/passports-were-a-temporary-war-measure/
But World War I brought harsh restrictions on freedom of movement.
In 1914, warring states of France, Germany, and Italy were the first to make passports mandatory, a measure rapidly followed by others, including the neutral states of Spain, Denmark, and Switzerland."
https://fee.org/articles/passports-were-a-temporary-war-measure/