I'm not sure when it happened, but it was around here I think that the branch became Catholic.
Wilhelm II was an only son. His uncle Paul had died at age one and his other uncle August had married morganatically. The next in line had to go back to a distant relative, Alexander, and his line. Alexander, though, had contracted a morganatic marriage in 1835 with Grafin Claudine Rhedey. Their children were granted the surname of 'Teck'. Alexander's son, Francis, married Princess Mary Adelaide of Cambridge, in 1866. (Queen Victoria created him Duke of Teck with the rank of 'Highness' in 1871) Their first child, Victoria Mary 'May', would become Queen of England in 1910 so it didn't work out too badly for this line considering Alexander's great-great-granddaughter sits on the throne of Great Britain while the Wurttemberg throne has been gone for almost 90 years.