Battle of Stalingrad strategic petroleum resources for Germany. The expansion of objectives was a significant factor in Germany's failure at Stalingrad, caused by German overconfidence and an underestimation of Soviet reserves. The Soviets realized that they were under tremendous constraints of time and resources and ordered that anyone strong enough to hold a rifle be sent to fight. Army Group South was selected for a sprint forward through the southern Russian steppes into the Caucasus to capture the vital Soviet oil fields there. The planned summer offensive, code-named "Fall Blau" (Case Blue), was to include the German 6th, 17th, 4th Panzer and 1st
Russian given name (calendar or Christian names, usually modified) and non-canonical. The 14th century was marked by the elimination of non-canonical names, that ended by the 18th century. In the 20th century after the October Revolution the whole idea of a name changed. It was a completely new era in the history of Russian names, marked by significant changes in common names. The names of popular saints are known as "calendar names" from their occurrence in the Eastern Orthodox liturgical calendar. A common custom is to name the baby for the saint who is the patron over their birthday. Such names include Ivan