siblings of Alonzo xx

half siblings maternal 2 half siblings paternal 15
  half siblings maternal (2)
  half siblings maternal (2)
  half siblings paternal (15)

half siblings maternal

broodmare Across the Flat xx (Thoroughbred, 1937, from Fairway xx)

Across the Flat xx
gender-female
1937

Fairway xx / Sardanapale xx

broodmare Bonaroba xx (Thoroughbred, 1936, from Bolingbroke xx)

Bonaroba xx
gender-female
1936

Bolingbroke xx / Sardanapale xx