BattleTech Field Manual: Crusader Clans (1998)

From the back of the book:

Nearly three hundred years ago, the Star League was torn apart when the lies and deceits of the petty House Lords launched the Inner Sphere into endless war. The Great Father Aleksandr Kerensky led our forefathers, the remnants of the righteous Star League army, away from that chaotic despotism. In turn, his son Nicholas forged us into the Clans: a society dedicated to becoming the greatest fighting force in all of history. We grew stronger with each generation, awaiting the day when we would return to the Inner Sphere to save it from itself.

Now is the time of the Return. Some among the Clans oppose the Crusaders' campaign of conquest, but we know that true enlightenment can only come to the misguided rabble of the Successor States through total subjugation. We will crush their honorless armies with our OmniMechs and plant the flag of the Clans on sacred Terra. Only then will the true Star League have returned to the Inner Sphere.

User comment:

The companion volume to the Field Manual: Warden Clans, this volume follows up on earlier books dedicated to the Clans and gives more detail on the seven Clans identified as being Crusader clans at the time of printing. More detail is given on the five Clans that hadn't been covered in earlier sourcebook at the time, and with those Clans comes detail on more new equipment, 'Mechs and Battle Armour not seen before in the Inner Sphere.

This sourcebook is out of print, and hasn't been released in electronic format by the current license holder.