Battle of Dien Bien Phu

Guns on the forward slopes

On the afternoon of 13 March 1954, General Võ Nguyên Giáp's forces began their full offensive at Điện Biên Phủ, opening accurate artillery fire from camouflaged positions in the hills around the French camp.

The bombardment struck French artillery positions, command posts, the airstrip and the northeastern strongpoint the French called Béatrice — Him Lam to the Vietnamese.

Many of the guns were concealed on forward slopes and aimed directly into the valley rather than firing blindly over the mountains, which is why locating and engaging them defeated French counter-battery work.

Fifty metres of trench

Việt Minh infantry followed the bombardment with a direct assault on Béatrice. Their approach trenches had reached to within approximately 50 metres of the French positions.

A shell hit the French command bunker early in the attack, mortally wounding Lieutenant Colonel Jules Gaucher and disrupting the northeastern defence. Béatrice was held by roughly 750 defenders; the cited U.S. Army history reports 194 legionnaire survivors.

By midnight

Béatrice had fallen to the Việt Minh 312th Division before midnight, giving them the first major breach in the French outer defences.

Gabrielle — Độc Lập — was attacked in the following phase rather than falling alongside it. The airstrip was already under sustained fire, but parachute supply missions continued through the siege, which ran until 7 May.