Japan’s large-scale invasion of China is generally dated to 7 July 1937, with the Marco Polo Bridge (Lugouqiao) Incident near Beijing, which escalated into the full Second Sino-Japanese War.

Quick context

  • On 7 July 1937, Japanese and Chinese troops clashed near the Marco Polo Bridge outside Beijing.
  • This skirmish rapidly expanded into a full-scale invasion, with Japanese forces occupying much of northern and coastal China over the following months.
  • Some historians also note that Japan had already occupied Manchuria in 1931, so aggression began earlier, but 1937 is the standard date for the full invasion of “China proper.”

In short: Japan’s full invasion of China is usually said to have begun on 7 July 1937, after the Marco Polo Bridge Incident.

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