Complex sentence: Berenice I (c.340 BC--between 279 and 268 BC) was a Greek Macedonian noblewoman and through her marriage to Ptolemy I Soter, became the second queen, after Eurydice, of the Ptolemaic dynasty of Egypt.
Split into simpler sentences: Berenice I (c.340 BC--between 279 and 268 BC) was Queen of Egypt by marriage to Ptolemy I Soter. She became the second second queen, after Eurydice, of the Ptolemaic dynasty of Egypt.