The actual Empire of the Iron Throne itself has also grown greatly; Tyrosh was conquered after a long campaign and Myr:
Was utterly conquered. The Myrese were chronically bankrupted by wars with Westeros they could not afford to win or lose and very soon began to fall apart as a state; independent Lords seizing power from the dying Myrese state, deprived of its monetary lifeblood. The last nail in the coffin has to be when during a siege of the city of Myr itself the Iron Throne army captured the entire unlanded living family of Magister Orbelo. Orbelo was happy to oblige me in turning over Myr to the Iron Throne. He died of failure. He was replaced by one of his daughters, as appointed by me. Also in the background is the first great civil war of Westeros since the first Baratheon rebellion and Ormund the Greatstag's reclamation of the fractured Kingdoms. I figured that letting Baratheons be Lord Paramount wouldn't be an issue because Baratheons are Baratheons. Then Lord Harlan Baratheon of the Reach declared war on Princess Cyrenna Baratheon of the Dorne. Princess Cyrenna demanded Benjicot's help and Harlan was getting belligerent so I joined the war on her behalf; the Reach held a significant number of my soldiers so I mobilized everything.
I requested Lord Lyonel Baratheon of the Vale join me in the war against the Reach to make this war end sooner. Lord Lyonel agreed, and raised his armies.
At which point he declared war on me. This cut off Northern reinforcements from reaching the south and also balanced the scales of troop numbers; 350,000 troops were commanded between the Vale and the Reach whilst the Crown had mobilized 400,000 troops. Though the troop numbers were similar, the Iron Throne still held the superior navy and superior commanders. The Vale and the Reach temporarily held the advantage as they had sandwiched the Iron Throne's troops between two fronts and had also divided many of the Throne's troops. Te Reach also had a fine share in the overseas Empire, making it the first global war as Benjicot and Harlan troops fought from the Iron Islands to Ibben and Sothyros. The war finally ended when Dragonstone landed on the beaches of the Vale, breaking the Vale's Fortress-like hold over its mountain. Soldiers returning to Westeros from Myr likewise conducted a landing in Highgarden, creating a second front for the Reach's own advancing soldiers. With the tables turned, both Baratheons began to crumble into defeat.
During this lengthy war however, many people died. Worse still many of the lands I had conquered in Essos in addition to some Summer Island territories had regained independence.
So began the reconquering. In addition all the Kingdoms owned by Benjicot were changed to primogeniture, though this somehow managed to piss off literally everyone except my firstborn. Major revolts are still happening basically every year and despite Benjicot ruling an Empire larger than Queen Megga the Great, because he is so unpopular from changing the succession law the Lords are all withholding many troops and ostensibly the Lords are only willing to provide 300,000 troops for the cause whilst Megga enjoyed half a million.
The Empire has expanded significantly; enjoying the great political collapse of the Free Cities that is inevitably following Iron Throne invasions and diplomats. When I set about the goal of bankrupting the Free Cities I had no idea that bankrupting them would actually result in their falling apart before I even began the proper invasions to take over their lands. Right now Braavos is a mess of independent city states, Pentos has had its first city gain independence from the main Fatherland, Qohor has lost its first war with the Iron Throne (and its first county), Norvos is on the doorstep of the Northern exspansion and Lorath is still relatively safe until I have enough of their trade posts to embargo them.
Most pleasingly is that the great Dothraki khalasar has begun to fracture into various individual Khalasars. My spymaster had some role in sowing dissent amongst the Khals; I'm not sure whether he was the main driving force or merely a catalyst to the Rommo Khalasar's decline. Khal Rommo was heavily bankrupt due to his inability to sufficiently fund his massive army (and he needed to continuously expand his Empire to keep his riders united) and so when the other Khalasars began gaining their independence he could not stop them. Conveniently this has left me with a Western buffer of Khalasars that will allow me to take Qohor without having to share it with Rommo. A territory was also taken in the far east after I found there was a kid with a strong claim in my court; if I can hold onto it I'll use it to expand into the East but otherwise I don't really mind if it's eventually reconquered or not. I'm more concerned in making sure the Khalasars continue declining and the Iron Throne can continue consolidating its power.
Cyan = Iron Throne
Scarlet = Free Cities and remnants
Pink = Independent Khalasars
Green = Khal Rommo
Dark red = Slaver cities
Yellow = Far east