The Most Succesfull Succesor

[cezarip]

I disagree, Seleukos I rapid come back, after Monophthalmos took over, was all due to the support he had with the locals, since he favoured the Babylonians economically during his satrapal rule...
More over all the "revolts" were dynastic struggles, where brothers (just thanks to the local support they managed to gather in their "domains") fought for the seat of Basileus of Asia...

The Ptolemaioi after Raphia had to face insurrections from the very locals who fought in the phalanx, as they became more aware of the privileges the ruling class had; all backed by the rural population who felt even more oppressed (losing the territories outside of Egypt meant an heavier burned on the local resources)...
And around the same time, even the Thebaid revolted and managed to create a kingdom with two local pharaohs...

All in all the Ptoleis from the second century BC onwards relied on help or opportunities from other "nations", and even when they managed to regain control of the Thebaid, they had to leave and epistrategos, who was pretty much independent...

Well more or less, the period of "glory" for both kingdoms was gone after about 160-150 BC when the growing power of Rome started imposing the rules in Syria and Egypt. Starting with this point, the power of both declined until in about 65 BC the last remnants of Seleucid territory becomes Roman province. Although under heavy roman control/protection the last Ptolemy (Cleopatra) retained the royal title to the end (30 BC). Ptolemaics outlast the Seleucids.

When I said that Seleucid power was "unfocused" I meant exactly that there were enough "competitors" to the throne that had/gathered/obtained/retained enough (local) power to challenge the authority of the king either through revolt or open war. Of course this happened also in Egypt but I get the feeling it was less frequent, at least at the beginning.

Let's see: WARNING WALL OF TEXT!

Spoiler Alert, click show to read: 

Seleucids:
1. Seleucus Nicator - assassinated 281 BC moves his capital to Syria (the starting point of loosing the grasp on Bactria and Parthia, my opinion).
2. Antiochus I Soter - looses Northern Phrygia/Galatia and North-western Lydia/Pergamus.
3. Antiochus II Theos - Bactrian and Parthian revolt. Poisoned by ex-wife Laodice I.
4. Seleucus II Callinicus - quite resourceful king but defeted at Ancyra looses control of land beyond Taurus and Hyrcania to Parthians.
5. Seleucus III Ceraunus assassinated by his officers, 223 BC.
6. Antiochus III the Great - Media and Persis revolt, recovered later. Restores authority in east (Parthia/Bactria) and meets success against Egypt. Makes the mistake of provoking the Romans, pays no heed to Hannibal and gets defeated at Thermopylae and Magnesia. Dies pillaging the temple of Bel.
7. Seleucus IV Philopator - murdered by Heliodorus.
8. Antiochus IV Epiphanes - stopped by the Romans from conquering Egipt. Religiously intolerant his actions lead to the Maccabean Revolt.
9. Antiochus V Eupator - killed by Demetrius.
10. Demetrius I Soter - defeats the Maccabeans. Timarchus, the Median satrap seeks independence but fails. Killed by Alexander Balas and the Jew forces.
11. Alexander Balas - killed by his own offices.
12. Demetrius II Nicator- regains his throne with the backing of Ptolemy VI Philometor. Empire divided between him and Antiochus VI Dionysus. Defeated by Parthians.
12. Antiochus VII Euergetes - initial success in Palestina and against Partians but soon defeated by Phraates II. Seleucids controlled mostly only Syria at this time.
14. Antiochus VIII Grypus - eastern provinces lost. Judaea independent. Revolt of his half-brother Antiochus Cyzicenus. Tyre, Sidon, Seleucia assume independence.
Civil wars follow.

Ptolemies:
1. Ptolemy IV Philopator - weak incapable king, but Egyptian forces win at Raphia as they did at Pelusium and Gaza. Secession of Upper Egypt, revolt of Horwennefer.
2. Ptolemy V Epiphanes - During early ears faces revolts and looses all possessions excepting Cyrenaica and Cyprus. Egyptian and Horwennefer's revolts repressed. Assassinated by his officers.
3. Ptolemy VI Philometor - Egypt saved from Antiochus IV Epiphanes by Romans. Reinstalled by the Roman Senate. Faced frequent rebellions. From now on the Ptolemies were increasingly dependent of Rome.
4. Ptolemy VIII Physcon - civil war with Cleopatra II, Harsiesi revolt crushed.
5. Ptolemy IX Lathyros - loss of Cyrenaica, times of trouble and civil Wars. Revolt in the Thebaid but oder restored during his life. Replaces the gold sarcophagus of Alexander with a glass one and melts the gold.
6. Ptolemy X Alexander - invades Judaea, reaches Damascus. Revolt in the Thebaid.
7. Ptolemy XI Alexander - lynched by the Alexandrians.
8. Ptolemy XII Auletes - end of the Seleucid empire. Avoids the annexation of Egypt by Rome. Takes an Egyptian wife in the effort to consolidate his power.
9. Cleopatra VII Philopator - THE Cleopatra. Sole ruler of Egypt. After her death Rome annexed Egypt.

I let you judge.