Outside school, the children mixed the high German with the local language Tok Pisin. They were not allowed to use Tok Pisin in school. The language that developed essentially used German words, with the grammar from Tok Pisin. Even after German rule in Papua New Guinea ended, the Vunapope mission station (which ran the school) remained in German hands with German as a school subject and even partly as the language of instruction. Since the children who developed Unserdeutsch often kept to themselves as mixed-race children and got married, they passed their Unserdeutsch on to the next generation and Unserdeutsch became the Creole language. After Papua New Guinea gained independence from Australia in 1975, most of the Unserdeutsch speakers decided to take on Australian citizenship and to emigrate to Australia, especially Queensland, because offices and posts in their homeland were to be filled by indigenous Papuans.