Ukrainian navy chief Denis Berezovsky swears allegiance to the pro-Russian regional leaders of Crimea in Sevastopol March 2, 2014 in this still image taken from video. Ukraine launched a treason case on Sunday against Berezovsky, the head of the navy, who surrendered his headquarters on Sunday in the Crimean port of Sevastopol on only his second day on the job. Berezovsky was shown on Russian television swearing allegiance to the pro-Russian regional leaders of Crimea. Russian forces have seized the Black Sea peninsula and told Ukrainian forces there to give up their weapons. Video shot March 2, 2014. REUTERS/Reuters TV

Over the last two months, the Ukrainian military command has seen almost weekly personnel changes. Shifting military leaders is often a way for politicians to try to control the military.

From Yanukovych’s installation of friendly commanders to today’s defection of the head of the Navy, here are some of the latest shuffles that are worthy of note.

There are a few major positions discussed here: the Chief of the General Staff, or the head of the military staff of the Ministry of Defense. The General Staff, The Ministry of Defense

On February 19, at the height of the Euromaidan protests, then-president Viktor Yanukovych fired the chief of the general staff (or head of all armed forces) Volodymyr Zamana and replaced him with Yuriy Illyin. Reports say the move was made because Zamana refused to react to protest-related violence with force.

Shortly after Yanukovych fled Kiev on February 22, Ilyin issued a statement saying “As an officer I see no other way than to serve the Ukrainian people honestly and assure that I have not and won’t give any criminal orders.”

With the government now controlled by opposition forces, Ilyin was dismissed himself on February 28, after reportedly suffering a heart attack. Acting president Oleksandr Turchynov replaced Ilyin with Lieutenant General Mykhailo Kutsyn, the former deputy minister of defense.

Ilyin is still an active part of the Ukrainian Navy and has expressed regret today that “Ukrainian soldiers and sailors are hostages of this situation.”

On March 1, Rear Admiral Denis Berezovsky was named commander-in-chief of the Ukrainian Navy. Despite being a small force, the Ukrainian Navy is playing a huge role in the Crimea crisis. The Navy is based out Sevastopol, the same city the Russian Navy’s Black Sea Fleet is based. It’s a hub of pro-Russian sentiment.

After just one day as commander of the Navy, Berezovsky “defected” and pledged his allegiance to the pro-Russian Crimean government and the “Crimean people.” Russian forces had surrounded the central headquarters of the Navy in Sevastopol and Berezovsky laid down weapons and surrendered.

In a press conference today, Berezovsky said “I vow to strictly follow orders from the commander-in-chief of the Autonomous Republic of Crimea and hero city of Sevastopol, as well as orders by military commanders appointed by them, demands placed by the military code.”

That commander-in-chief is the unrecognized prime minister of Crimea, Sergey Aksyonov, who also ordered all Ukrainian Navy personnel to ignore orders coming from Kiev and from the “illegally appointed Defense Minister Tenyukh.”

The Prosecutor General’s Office of Ukraine has now charged Berezovsky with treason. Rear Admiral Sirhiy Hayduk has been named his replacement. Naval officers found their headquarters occupied and were blocked from entering work. The Ukrainian Coast Guard has also withdrew its ships from two Crimean ports and moved them elsewhere.

Even though Berezovsky defected from Ukraine, it appears the rest of the Navy is still loyal to Ukraine. There are reports that the Ukrainian Navy flagship Hetman Sahaydachny defected to the Russians, but the Ukrainian Ministry of Defense denies this. The Hetman Sahaydachny has been running anti-piracy drills off the coast of Somalia and is now returning to the Ukraine after resupplying in Greece.

Askyonov has announced the creation of the Crimean Navy and it appears the government in Crimea is making an attempt at full independence. The Crimeans plan to have a referendum for independence on March 30.

As of March 2, the most volatile positions in the Ukrainian military stand as:

CHIEF OF GENERAL STAFF: Mykhailo Kutsyn, appointed February 28

DEFENSE MINISTER: Ihor Tenyukh, appointed February 27

COMMANDER OF THE NAVY: Serhiy Hayduk, appointed March 2