The son of Ptolemy IX became the ward of his grandmother [Cleopatra III] when his father was exiled to Cyprus (107 BCE). Like his younger cousin, Ptolemy XI, Auletes ["the Piper"] was sent to the isle of Cos where he was taken hostage by Mithradates VI of Pontus  (88 BCE). In the wake of the deaths of Berenice III & Ptolemy XI (80 BCE), however, he was recalled to Alexandria & installed as king (76 BCE).

Since Auletes was never popular in Alexandria, he had to spend most of his time & fortune gaining the support of Romans. When his legitimacy was challenged by Roman senators who sought to annex Egypt, he actively courted the favor of Roman consuls by sending troops to Judea to support Pompey & bribing Julius Caesar to pass a resolution in the Senate recognizing his kingship. The price of Roman support, however, was relinquishing Ptolemaic claim to Cyprus. To avoid opposition in Alexandria, Auletes went to Rome (58 BCE), leaving his wife [Cleopatra V] & oldest daughter [Berenice IV] to rule Egypt. In his absence, Alexandrians declared his daughter sole ruler. Auletes countered by bribing Gabinius, the governor of Syria, to use the Roman army to restore him to the throne of Egypt.  Once reinstalled (55 BCE), he had his daughter murdered, leaving her younger sister [Cleopatra VII] & brother [Ptolemy XIII] as his primary heirs.

References: Josephus, Antiquities 14.98. 
                   ______, War 1.75.
                   Cassius Dio, Roman History 39.12-14, 55-58.    

Other resources on line:

• Berenice III, Ptolemy X Alexander II & Ptolemy XI (Auletes) - chapter 12 of E. R. Bevan's 1927 classic The House of Ptolemy [on Bill Thayer's Lacus Curtius]. *

• Cassius Dio's Roman History Book 39 - 2nd c. CE Roman chronicle of the exploits of Julius Caesar includes accounts of Ptolemy's exile & restoration [on Lacus Curtius].

• Ptolemy XII - Christopher Bennett's annotated Egyptian Royal Genealogy provides detailed references to sources.

• Ptolemy XII Auletes - Jona Lendering lists biographical data & key dates [Livius: Articles in Ancient History].

• Ptolemy XII Auletes - entry in Wikipedia's web.

* [Note: Bevan's numbering of the Ptolemies differs since he drops Ptolemy VII from classical lists because there is no historical evidence of his reign].

Silver tetradrachma minted in Alexandria in 69 BCE with diademed image of Ptolemy [I or XII?]. The reverse bears the traditional Ptolemaic eagle & inscription: Ptolemaiou Basileos ["of king Ptolemy"].

For high resolution images of this and other coins of Ptolemy XII, see Ancient Coinage of Egypt, Ptolemy XII in David Surber's comprehensive ancient coins website: Wildwinds.