The Knights of the Silver Sword were established in M.36 as a Sucessor Chapter of the Imperial Fists. The First Chapter Master, Beli Mawr forged a great sword he named Excalibur. This chapter heirloom can only be grasped by the Master of the chapter. Any lesser mortal who attempts to pull the sword free from it's sacred resting place has his hand seered by scalding heat. The Chapter Master bears the Title of the Pendragon, the First Dragon, and wears an ancient suit of Artificier Armour, covered in littanies and prayers. The current Chapter Master is Arthur Castus. He drew Excalibur from it's stone anvil at a young age. At the time, he was the youngest Chapter Master to bear Excalibur, and has now led the Knights of the Silver Sword to victory after victory for nearly five centuaries.
Unlike most Codex Chapters, the compainies have names rather than numbers. For example, the first company is called the Dragon Company, the second company are the Pegasus Company, and so on. Each Captain bears a relic blade as a badge of office and a promise to his brother marines that he will be in the thick of the fighting, slaying enemies of the Imperium and the Emperor. Their Chapter iconography also divergest from the Codex Astartes; On their left shoulder pad, they carry the Chapter symbol of the Silver Sword as normal, but rather than a tactical, assault, or devestator symbol on their right shoulder pad, the bear the heraldry of the Company (The Pegasus company display a pegasus, etc.) Their squad symbol is shown on the left knee pad, and the squad number on the right.
The Knights of the Silver sword excell at close quaters and short range fire fights. They have more sternguard veterains than any other chapter, attaching a full squad of 10 to almost every company.
Chapter Organisation
CHAPTER COMMAND
Arthur Castus, The Pendragon, Lord of Dumnomia, Master of the Knights of the Silver Sword
Master of Sancity; Tewdric of Elmet (Cassius)
Honour Guard; 30 Paladins, 1 venerable Dreadnought, Brother Ancient Cerdic
1 Land Raider Crusader "Llamrei" (Chournos)
(1st) Dragon Company
Chapter Champion, Captain Lancelot (Sicarius)
"The Blood of Deamons annoint our swords."
5 Command Squad
50 Sternguard
20 Vanguard
30 Terminators
3 Land Raiders (Varying types)
5 Dreadnoughts (Varying Types)
(2nd) Pegasus Company
Captain Gawain, Regent of Camelot
"We are the Knights of Battle, the Lords of War."
5 Command Squad
60 Tactical Marines
20 Assault Marines
20 Devestaor Marines
1 Dreadnought
1 Ironclad Dreadnought
10 Sternguard
(3rd) Stag Company
Captain Tristran (Shrike)
"We strike with the Precission of the Lord of Stags."
5 Command Squad
60 Tactical Marines
20 Assault Marines
20 Devestator Marines
3 Dreadnought
10 Vanguard
(4th) Boar Company
Captain Bors (Lysander)
"They shall feel my Wrath!"
5 Command Squad
60 Tactical Marines
20 Assault Marines
20 Devestator Marines
3 Ironclad Dreadnoughts
10 Sternguard
(5th) Axe Company
Captain Dagonet
"I fear no Evil, for I am fear Incarnite!"
5 Command Squad
60 Tactical Marines
20 Assault Marines
20 Devestator Marines
2 Dreadnoughts
10 Sternguard
Reserve Companies
(6th) Wolf Company
Captain Defel
"Fear the Wolf's Howl, for that is when we hunt!"
5 Command Squad
80 Tactical Marines
20 Bikes
10 Vanguard
10 Sternguard
4 Dreadnoughts
(7th) Lion Company
Captain Galahad
"By the Fury of the Emperor!"
5 Command Squad
80 Tactical Marines
10 Land Speeders
20 Sternguard
4 Ironclad Dreadnoughts
(8th) Hawk Company
Captain Lucan (Kor'sarro Khan)
"Ride out, For the Emperor and the Pendragon!"
5 Command squad (Bikes)
80 Bikes
10 Land Speeders
10 Vanguard
2 Dreadnoughts
(9th) Castle Company
Captain Bedivere (Pedro Kantor)
"While I breathe, no enemy shall breech these walls!"
5 Command Squad
100 Devestator Marines
20 Sternguard
5 dreadnoughts
5 Ironclad Dreadnoughts
(10th) Arrow Company
Scout Master Owain (Telion)
"We are the hounds of Vengance, sent to hunt."
80 Scouts
20 Scout Bikes
ARMOURY
Master of the Forge: Sagramor
30 Techmarines
20 Predators
9 Vindicators
5 Whirlwinds
22 Land Raiders
APOTHECARION
Master of the Apothicarion: Valiant
12 Apothecaries
LIBRARIUS
Chief Librarian: Merron
4 Epistolaries
10 Codiciers
Yes, I am doing a whole smegging chapter 
It's gonna take me a while, bit it's gonna be worth it. I'm working on the fluff at the mo, so I should have that up in a few days time.