London's Cainite population is in a continual state of flux. While there is a "core group" of vampires (mostly powerful elders and their favored childer), who dwell in the city for most of the time, it also has a far larger-than-average transient population. London is a major trading hub, capital of the mortal kingdom, and "capital" of a Cainite power bloc which not only dominates southern England and some parts of northern France, but has significant influence in northern England, Scotland and south Wales as well. Vampires across a broad swathe of northern Europe have ties, interests, and representatives there.
Unsurprisingly, the Ventrue are the most numerous and politically powerful clan in London, influencing both the nobility and the increasingly powerful merchant class. They never showed a great deal of interest in the Church, perhaps because of Mithras' visceral prejudice against Christianity.
Before the War of Avalon, the Lasombra were the ones who filled that gap. The clan broadly divided into two factions, the "Pious" Lasombra, almost exclusively walkers on the Road of Heaven, who involved themselves with church affairs out of genuine religious conviction, and the "Worldly" Lasombra, largely walkers on the Road of Kings, who saw the Church as a vehicle for their own ambitions. Both were almost completely wiped out by the Inquisition during the War of Avalon, and the Clan of Shadows now has almost no presence in London.
The Toreador, by contrast, tend to be less interested in the political and spiritual affairs of the church than with its architecture, and survived the Inquisition's efforts much better. The London Toreador are disproportionately artisans, usually stonemasons, with a great involvement in church and cathedral building.
Only two members of the Cappadocian clan presently dwell in London. The first, Roger de Camden, is a Norman nobleman and former Crusader. Despite his youth, he has earned a position as Mithras' Seneschal thanks to his considerable administrative flair and political acumen. The second, Adam Bell, is a devoted follower of the Road of Heaven who claims the lazar-house of St Giles, outside the city limits, as his Domain.
Before the War of Avalon, the Brujah were a political force to rival the Ventrue. Their leader, Lord Magnus, was a reputed survivor of Carthage, a powerful Methuselah whose subtle opposition to Mithras was never quite overt enough to give the Prince an excuse to exile him. Magnus was a casualty of the War of Avalon, and Mithras seized the opportunity to neutralize the Brujah as a political threat. The clan's presence in London is now largely limited to a few neonates and ancillae, most of them scholars on the Roads of Heaven and Humanity, with few political ambitions.
There are no Tzimisce presently in London, although the former exile, Lord Raguel Vitaezul, now returned to his ancestral homeland, is a distant ally of the fief.
Only one member of Clan Assamite, Don Leon St Gabriel, makes his haven permanently in London, although Mithras receives the clan's envoys with something approaching warmth - or at least, as close to it as he ever gets.
No such warmth is extended towards the Followers of Set, none of whom reside openly in London. Mithras regards the clan with open suspicion, and seldom gives its members leave to remain in the city for any length of time.
The Gangrel, by contrast, are both relatively numerous and relatively powerful. The clan's leader, Chalice of Mercia, is one of Mithras' key lieutenants, a prominent member of the Saxon faction who helped the Methuselah defeat the Norman Triumvirate. Chalice's niece-in-blood, Megan of Bristol, is one of the city's richest merchants. The Knights of Avalon, personally sponsored by Mithras, is a prominent Cainite chivalric order. The Gangrel's wealth and influence makes them look more like a High Clan than a Low, although their position owes a great deal to the Prince's personal patronage, something that neither they nor he ever forget.
The Malkavians are rarer, but have influence in a surprising number of places. Their leader, the Jackdaw, is a Methuselah in his own right and London's principal crime lord. Other members of the clan serve as spies, scholars, and ashen priests, in both the mortal and immortal worlds. Their uncanny insight largely protected them from the Inquisition during the War of Avalon.
The Nosferatu are also quite populous. The majority of the clan are walkers on the Road of Heaven, many of whom look on the Cappadocian Adam Bell as their spiritual mentor. A smaller group, mainly followers of the Road of Kings, server Mithras as spies and assassins, including the Prince's spymaster, Richard de Worde. Another group of pious Nosferatu have an unusual alliance with Clan Toreador, informally known as the "Guild of Stone Masons", driven by their shared interest in church and Cathedral-building.
The Ravnos, like the Followers of Set, have no acknowledged presence in London, and Mithras seems to prefer it that way.
He'd undoubtedly prefer to say the same of the Tremere, but their new-found dominance of the north of England makes that unrealistic. The Prince has allowed them to establish a small chantry and embassy on London Bridge, but watches them like a hawk and allows them very little leeway. The chantry's Regent, Artos bani Tremere (or "Arthur the Lame", as he is more commonly known), is well aware of Mithras' distrust, and keeps the few underlings the Prince allows him on a very short leash.