Russia began its military operation to seize control of Crimea on 20 February 2014, and completed the formal annexation on 18 March 2014.

Key dates at a glance

  • 20 February 2014: Start date engraved on Russian medals “For the Return of Crimea,” widely treated as the beginning of the operation.
  • 27 February 2014: Armed men without insignia seize key government buildings in Crimea, raising Russian flags.
  • 16 March 2014: Russia-organized referendum held in Crimea, not recognized as legitimate by Ukraine and most of the world.
  • 18 March 2014: Treaty signed in Moscow to incorporate Crimea and Sevastopol into the Russian Federation; this is the formal annexation date.

Why there’s confusion about “when”

People often ask “when did Russia invade Crimea?” but the answer depends on what you mean by “invade”:

  • If you mean covert military operation begins : late February, with 20–27 February 2014 as the critical window.
  • If you mean buildings and territory taken over by force : seizure of the Crimean parliament and government buildings on 27 February 2014 is often cited.
  • If you mean legal/official annexation date claimed by Russia : 18 March 2014.

In international discussions, the whole sequence is usually described as the 2014 Russian annexation of Crimea , starting around 20 February 2014 and culminating in the annexation on 18 March 2014.

Forum and “latest news” angle

  • The question “why did Russia invade/annex Crimea in 2014?” and whether locals supported it is still actively debated in online forums like Reddit, with posts and discussions continuing well into 2025.
  • Debates usually cover strategic issues (Black Sea Fleet, Sevastopol, NATO), identity and language politics, and how free or meaningful the 2014 referendum actually was.

In many recent forum threads, you’ll see people arguing over whether this was an “invasion,” a “reunification,” or something in between, reflecting sharply different political narratives.

Quick SEO-style summary (for your post)

  • Main keyword: when did russia invade crimea
  • Core answer: Russia’s operation to take Crimea began around 20 February 2014, with armed forces seizing key sites by 27 February, and the peninsula was formally annexed on 18 March 2014.
  • Temporal hook: This remains a central flashpoint in the wider Russo‑Ukrainian war and is frequently referenced in discussions about the 2022 full‑scale invasion and ongoing negotiations.

TL;DR: Russia’s move on Crimea unfolded over weeks in early 2014, but the two dates most often quoted are 20 February 2014 (start of the operation) and 18 March 2014 (formal annexation).

Information gathered from public forums or data available on the internet and portrayed here.