The Prophet ﷺ said: An estate which was divided in pre-Islamic period may follow the division in force then, but any estate in Islamic times must follow the division laid down by Islam.
قَالَ النَّبِيُّ ﷺ كُلُّ قَسْمٍ قُسِمَ فِي الْجَاهِلِيَّةِ فَهُوَ عَلَى مَا قُسِمَ لَهُ وَكُلُّ قَسْمٍ أَدْرَكَهُ الإِسْلاَمُ فَهُوَ عَلَى قَسْمِ الإِسْلاَمِ