sentences:  It contains works of Rococo art by some of the leading Italian artists of the 18th century.Its origin dates to 1590 when John Francesco di Sangro, Duke of Torremaggiore, after recovering from a serious illness, had a private chapel built in what were then the gardens of the nearby Sansevero family residence, the Palazzo Sansevero.The building was converted into a family burial chapel by Alessandro di Sangro in 1613 (as inscribed on the marble plinth over the entrance to the chapel).