The House and Merit Order of Duke Peter Frederick Louis (German: Haus und Verdienstorden von Herzog Peter Friedrich Ludwig) or proper German Oldenburg House and Merit Order of Duke Peter Frederick Louis (German: Oldenburgische Haus- und Verdienstorden des Herzogs Peter Friedrich Ludwig) was a civil and military order of the Grand Duchy of Oldenburg, a member state of the German Empire. The order was founded by Grand Duke Friedrich August of Oldenburg on November 27, 1838. It became obsolete in 1918 after the abdication of the last grand duke.RR
