Final answer:
The Allied leaders began holding conferences in 1943 to coordinate their war efforts, plan for the post-war world, and discuss important issues. These conferences allowed them to build relationships and exchange ideas.
Step-by-step explanation:
The Allied leaders began to hold conferences starting in 1943 for several reasons. These conferences allowed them to coordinate their efforts in the war and plan for the post-war world. They discussed important issues such as opening a second front in Europe, dividing Germany, addressing relations between the Allies, and preventing future conflicts. The conferences also provided an opportunity for the leaders to build relationships and exchange ideas.