his leading core overran the outer defenses but did not capture the cockade city i tself. toeral fair on -- failure saved theopportunity city. a grand assault by the unionists on june 18 was bloodily repulsed. even worse disaster befell the yankees less than a week later in their efforts to cut confederate communication south of the cockade city. those dual defeats on june 18 , 23rd and the mobile warfare of spring that had carried of the armies from the rapid than river to the appomattox. stagnated, operations into the slowness of summer, and the siege of petersburg began. this siege was not tactical. parallels and other facets that type of five european siege warfare. the infamous battle of the crater on july 30 was an aberration, totally uncharacteristic of the siege, yet petersburg unquestionably was a siege. on the higher planes of operations, strategy, and grand strategy. in essence, grant used the siege to fix the gray coats in place at petersburg and richmond, thus to deny lee the operational and strategic initiative, which the virginian have used to such advantage