Contrarily, having so firmly entrenched themselves into Greek affairs, the Romans now completely ignored the rapidly disintegrating Seleucid empire (perhaps because it posed no threat); and left the Ptolemaic kingdom to decline quietly, while acting as a protector of sorts, in as much as to stop other powers taking Egypt over (including the famous line-in-the-sand incident when the Seleucid Antiochus IV Epiphanes tried to invade Egypt). Who tried to invade Egypt in the famous line-in-the-sand incident?