House of Mecklenburg
The House of Mecklenburg-Strelitz survives to this day, descending from Duke George, the morganatic son of Duke George Alexander with Countess Natalia Carlow and nephew of Duke Charles Michael, who adopted him in 1928. George subsequently assumed the title "Duke of Mecklenburg" (Serene Highness) which was acknowledged by Grand Duke Frederick Francis IV of Mecklenburg-Schwerin. He was later given the style of "Highness" by the House of Mecklenburg-Schwerin. George's grandson Borwin is the present head of the House of Mecklenburg-Strelitz.