Castor and Pollux.

Castor (Κάστωρ) and Pollux (Πολυδεύκης) were twin brothers in Greek mythology. Also, they were called Dioscuri (Διόσκοροι, Διόσκουροι).

Leda (Λήδα) was Castor's and Pollux's mother. Tyndareus (Τυνδάρεος) (Tundáreōs) was Castor's father. Zeus was Pollux's father.

Timandra (Τιμάνδρα), Clytemnestra (Κλυταιμνήστρα) (Klutaimnḗstra), Helen of Sparta, Philonoe (Φιλονόη), and Phoebe (Φοίβη) (Phoíbē) were Dioscuri siblings.

These brothers were on the expedition of the Argonauts.

Castor and Pollux saved their sister Helen (Ἑλένη) (Helénē) of Troy.

There are different stories about Dioscuri.

Leda.

 Leda (Λήδα) was a character of Greek myths and legends. Her father was Thestius, king of Pleuronians in Aetolia. Her mother was Deidameia.

Leda married king Tyndareus of Sparta. She had several children: beautiful Helen, Clytemnestra, Castor and Pollux, Timandra, Phoebe and Philonoe. 

There are many paintings and sculptures and Leda.

Source of image:

https://www.shutterstock.com/es/image-photo/croatia-zagreb-7-may-2017-stamp-637486831

Source of image:

https://www.shutterstock.com/es/image-photo/russia-kaliningrad-19-april-2017-stamp-644669500

Source of image:

https://www.shutterstock.com/es/image-photo/queen-sparta-leda-preparing-date-swan-1710059170

Source of image:

https://www.shutterstock.com/es/image-photo/leda-swan-by-bartolomeo-amannatti-bargello-35636869

Source of image:

https://www.shutterstock.com/es/image-photo/turin-piedmont-italy-may-16-2012-1309272766