The Fellowship of the First and Second Rings
The second ring (rows b2:o2 and b15:o15, columns b2:b15 and o2:o15) - consisting of 48 pawns and 4 Knights.
The fun in drawing a correlation here between Sovereign Chess and Tolkien's original work is that, in the game, every piece has the potential to work FOR you, achieving your aims. Every color has the potential to be "in fellowship" to your overall goal of winning the game. Simultaneously, there is an OPPOSING power at work (your opponent) seeking to also use these pieces to work against you (much like how Tolkien's fellowship was in tension with itself).
The Sixteen Towers
This image is largely just making a simple play on Tolkien's "The Two Towers"- simply by counting the number of rooks on a Sovereign Chess board. But, it DOES reflect the variety of colors and opportunities that can be had at game's start!
There's also room for two observations that could be made here.
One is that ALL colors are shown. Meaning, if I am the White army, there is possibility for my controlling the Black Rooks in a game (and vice versa). Mind you, there are special criteria for this, but you won't find this in traditional chess.
The second observation is this: in Tolkien's narrative, Saruman begins by helping the Dark Lord take over Middle Earth and ultimately betrays Sauron by serving his own agenda (the "Two Towers" allied v. divergent). In Sovereign Chess, since colored pieces are not "your" pieces, but rather: pieces that serve you as long as you control them and can then be cast aside - or even "betray" you. The tension is this: do you work to save a colored piece under your control? Or seek it's capture (ala "kamikaze") for the greater good and so it might not be used against you?
The Return of the King
In Tolkien's work, "The Return of the King," there are several regime changes that might be highlighted. The Steward of Gondor is unseated. Sauron is defeated. Shadow is dispelled.
In Sovereign Chess, the regime change illustrated in this image is that of "Coup d'Etat". Upon reaching the promotion line on a Sovereign Chess board, a player may choose to replace a pawn of their color to a King. The initial King is then immediately removed from the board.