Sovereignty is being - allowing what is to fully be there, to not push away or pull toward, to not allow karmic knots to seemingly run the show. Of course, for nearly everyone, this takes some practice.
In meditation or 'spiritual' practice, this means allowing awareness to fully relax into itself - not allowing attention to be fully engrossed in thoughts (being "in your head"), regardless of how juicy they appear to be; not allowing attention to be sucked into a vortex of intense emotion and forgetting anything else exists; not allowing attention to ignore the entirety of your experience in favor of the itch, the pain in your in your neck, the tightness in your chest, or even "controlling" your breath.

Sovereignty "on the cushion" is allowing awareness to be with everything that arises, including brain fog, sleepiness, a sense of panic, "kundalini" movements, thoughts, and most importantly, the entire field of energy and silence that is all around you (and is you!) always. Maybe not an easy task, but certainly a simple one. Whether your practice is complex, involving visualization, mantra, and breath-counting practice, or a "basic" body scan meditation, resting first as awareness and allowing it all to be there is the key.
In a sense, sovereignty is also a form of discernment - noticing what is grabbing attention and making it seem smaller, versus being with every sensation, thought, emotion, and the deep silence all together. Can you discern what is true? (Hint: Truth needs no commentary. It is self-validating.)

I'll give you a quick example:
I begin a meditation by doing a quick body scan, allowing awareness to feel into the feeling all over my skin, in my muscles, my bones, the breath. Noticing the vibrations and energy through, my heartbeat, points of tension, etc. Suddenly, as awareness relaxes and becomes more encompassing of all of those things at once, I get a sense of tightness in my chest and a parade of thoughts occur. "Damn! I forgot to stop at the bank on my way home from work. I feel bad I still haven't gotten back to my friend who texted me 2 days ago. Remember when I was 10 and felt embarrassed reading that poem in front of the class?" Attention has been grabbed, and I may not even notice it has been grabbed for seconds or even minutes. At this point, I can do a re-scan of the body, or allow awareness to relax and more widespread again.
Now, I've been practicing this for a while, so the thought-train just isn't as juicy as often (and it calms down eventually, you'll notice). So, I am resting as awareness for quite some minutes, and my heart suddenly starts beating faster, I feel tightness, anxiety, or even a deep fear. I suddenly start to feel like my tight chest and anxiety are all that's there, and I can't notice my feet or breath, and then the thoughts come pouring in again. "I can't even do this right! Why am I meditating again? This is so dumb." Re-scan, relax, rinse, repeat.
What's happening here? It's the same old karmic knots! They secrete thoughts, feelings, unintentional body movements, sleepiness even though you woke up an hour ago and had your coffee already, and are just silently yelling over and over, "this isn't safe, I can't relax anymore!" This is how they show up in meditation and in life. Karmic knots secrete fear. They aren't true but they certainly know how to grab your attention. Practicing being aware of all of these things AND the breeze on your skin, the tingling in your toes, the saliva in your mouth, and the softness of your belly is all we're doing when I say "resting as awareness." It is fully safe, regardless of what the thoughts are telling you (you're just sitting there, after all!).

So, Sovereignty is also a deep knowing of safety. You - awareness - are always safe. Regardless of what's happening, you're just allowing it to be there. It may sound crazy to try to apply this to everyday life, but I promise, it is literally no different ever. Awareness doesn't ever go away. And you can relax into/as awareness any time.
Try it out :)
In Part 3, we'll briefly explore sovereignty in your daily life.