I'd not heard of Schaumburg-Lippe before!
It's a German principality - established in 1807 (before then, it had been a county first established in 1647, ruled by Counts). German monarchies were all abolished in 1918, and it became a state in its own right, being merged in to Lower Saxony in 1946.
The head of the house is called Alexander. This chap is descended from Prince Waldemar, the second son of previous head of the House, Prince Christian (who I think is either grandfather or great grandfather of current head)
I don't think he's a working royal in the British sense. He was born Mario-Helmut, and later changed his name to Mario-Max. He still uses his title, works as a writer, producer and director (according to imdb)