I've been playing a Roman/Byzantine game, starting from the Stamford Bridge bookmark in HIP. My original character was Nikephoros Melissenos, Strategos of the Thracesians (Western Asia Minor, the duchy directly to the east of Smyrna, landlocked), who starts the game as the brother-in-law of Alexios Komnenos & co. I've had a strange fascination with the Melissenoi family for some time now, as the oldest recorded Byzantine family, and one that never rose to the purple. It was nice to have the opportunity to play as them; also, their coat-of-arms is sweet.
Anyway, early on I decided to migrate from Thracesians to a duchy in Europe, since I feared the Turks would conquer Asia Minor and give me a game over early on. I sent my logothete to fabricate claims to Adrianople and my plan eventually included Nikephoros becoming Emperor after winning a claim to the throne in the battlefield, which may happen in HIP if a general is particularly successful. That never happened, unfortunately, even though Nikephoros was a legendary commander and Grand Domestic/marshall by the end of his life, and since then I've decided to stay away from the imperial throne.
The consequence of said decision was a mess, predictably. It seems the AI simply cannot hold the imperial throne on their own. Constantine X died one year into the game and his son Michael VII succeeded him. The throne swapped around a lot after that between several Doukai and even Komnenoi. Eventually, Romanos IV Diogenes became Emperor (the backbone of his army were the Melissenoi) and looked like he was going to be a good one, but he died one month later and his son Germanos succeeded him. He didn't last long, being replaced by a Komnenid, who was deposed by Alexios Komnenos around 1100, but who ruled for a year or so until his nephew was returned to the purple. The throne has returned to the Doukai by now (around 1120), inherited by the Komnenid's Doukas kids. I'll get a list for y'all later.
Anyway, Nikephoros Melissenos was a seasoned Roman general and became known as Nikephoros the Lion, as any good Eastern military aristocrat would. Under his rule, the Melissenoi shifted from Eastern to mostly Western military aristocrats; although the Thracesians were kept under their grip, the family's seat moved first to Adrianople and then to the Empire's second city, Thessalonica itself, and Nikephoros became the Doux of Thessalonica. In his career as general, he defeated Turkish invasions several times, particularly at the Battle of Melitene, although he only delayed the inevitable. Towards the end of his life, he was determined to claim the Imperial throne following a series of civil wars that left the Empire weakened; as the single respected (and respectable) commander and nobleman left, he felt it was his duty to take charge and enforce order to restore glory to Rome. Unfortunately, he became infirm and died before he could march against Constantinople.
His sucessor, Romanos Melissenos, was content to remain at Thessalonica, without his father's imperial ambitions. He became a strongman of the Doukid regime, sometimes serving as regent, though it was under one of his regencies that central Anatolia was lost to a jihad. Although Doux Romanos does not aim for the purple, he has consolidated his grip on Europe by claiming for himself Great Vlachia and by harboring Italian ambitions, that has seen a Sicilian princess married to his youngest son, Leon Melissenos. Romanos had two other older sons, Nikephoros and Basil, but the former was a hunchback forced into a monastery who died young, and the latter an unexceptional courtier at the Emperor's court. Leon, however, was a brilliant general and his father's appointed successor. He is expected to do great things once Romanos passes away.