siblings of Problem xx

full siblings 1 half siblings maternal 3 half siblings paternal 15
  full siblings (1)
  full siblings (1)
  half siblings maternal (3)
  half siblings paternal (15)

full siblings

stallion Theorem xx (Thoroughbred, 1824, from Merlin xx)

Theorem xx
gender-male
1824

Merlin xx / Trumpator xx