thumb|Western Campaign: 10–16 May 1940|alt=The attack began at 5:35 on the morning of 10 May 1940. Guderian personally attended the attack alongside 1st Panzer Division against Wallendorf in Luxembourg. Luxembourg, which had only maintained a token military force, was quickly overwhelmed, and 1st Panzer Division reached the Belgian border at Martelange by the afternoon. Großdeutschland had undertaken a paradrop mission on the other side of the Belgian border to gain a headstart on the armored units, but 1st Panzer Division caught up on the first day. 10th Panzer Division attacked towards Habay-la-Neuve and was opposed by the quick response of the French 3rd Colonial Infantry Division, although the 3rd Colonial did not manage to significantly impede the 10th Panzer's advance.
