 France ceded more than 90% of Alsace and one-fourth of Lorraine, as stipulated in the treaty of Frankfurt; Belfort, the largest Alsatian town south of Mulhouse, remained French.Unlike other member states of the German federation, which had governments of their own, the new "Imperial territory of Alsace-Lorraine" was under the sole authority of the Kaiser, administered directly by the imperial government in Berlin.Between 100,000 and 130,000 Alsatians (of a total population of about a million and a half) chose to remain French citizens and leave "Reichsland Elsaß-Lothringen", many of them resettling in French Algeria as Pieds-Noirs.