The British forces in North Africa had achieved a stunning victory over the much larger forces of the Italian Army, which had invaded British mandate of Egypt from Libya. The arrival of German forces under Rommel was intended to prevent a humiliating collapse, even if it was a minor sideshow for Hitler.
The German forces had managed to surprise the British forces in the Libyan desert with their first attack. Rommel writes home to his wife:
We’ve been attacking since the 31st with dazzling success. There’ll be consternation amongst our masters in Tripoli and Rome, perhaps in Berlin too. I took the risk against all orders and instructions because the opportunity seemed favourable. No doubt it will all be pronounced good later and they’ll say they’d have done exactly the same in my place.
We’ve already reached our first objective, which we weren’t supposed to get until the end of May. The British are falling over each other to get away. Our casualties small. Booty can’t yet be estimated. You will understand that I can’t sleep for happiness.
From ‘The Rommel Papers’, a collection of original letters and documents contemporaneously written or dictated by Rommel throughout the campaign: