Publius Servilius Casca Longus，公元前43年的罗马论坛报，是刺客的名字，他于公元前44年3月底第一次袭击了朱利叶斯·凯撒。袭击的象征是卢修斯·蒂利乌斯·西伯抓住凯撒的圆领上衣并从他的脖子上拔下。紧张的卡斯卡随后刺伤了独裁者，但只擦伤了他的脖子或肩膀。

普布利乌斯·塞维利乌斯·卡斯卡·隆格斯（Publius Servilius Casca Longus）以及他的兄弟卡斯卡（Casca）都是在公元前42年自杀的同谋者之一。这种光荣的罗马式死亡方式是在菲利普战役之后出现的，当时刺客（被称为共和党人）的力量输给了马克·安东尼（Mark Antony）和屋大维（Augustus Caesar）。

这里有一些古代历史学家的文章，描述了卡斯卡在刺杀凯撒事件中所扮演的角色，并启发了莎士比亚对这一事件的看法。

苏埃托尼乌斯

"82 As he took his seat, the conspirators gathered about him as if to pay their respects, and straightway Tillius Cimber, who had assumed the lead, came nearer as though to ask something; and when Caesar with a gesture put him off to another time, Cimber caught his toga by both shoulders; then as Caesar cried, "Why, this is violence!" one of the Cascas stabbed him from one side just below the throat. 2 Caesar caught Casca's arm and ran it through with his stylus, but as he tried to leap to his feet, he was stopped by another wound."

普鲁塔克

"66.6 But when, after taking his seat, Caesar continued to repulse their petitions, and, as they pressed upon him with greater importunity, began to show anger towards one and another of them, Tullius seized his toga with both hands and pulled it down from his neck. This was the signal for the assault. 7 It was Casca who gave him the first blow with his dagger, in the neck, not a mortal wound, nor even a deep one, for which he was too much confused, as was natural at the beginning of a deed of great daring; so that Caesar turned about, grasped the knife, and held it fast. At almost the same instant both cried out, the smitten man in Latin: 'Accursed Casca, what does thou?' and the smiter, in Greek, to his brother: 'Brother, help!'"

尽管在普卢塔克的版本中，卡斯卡精通希腊语，并在紧张的时刻恢复使用希腊语，但卡斯卡在莎士比亚的《凯撒大帝》（Julius Caesar）中的形象让人耳熟能详（在第一幕第二幕），他说：“但就我而言，我对卡斯卡的理解是希腊语。”上下文是卡斯卡在描述演说家西塞罗的演讲。

大马士革的尼古拉斯

"First Servilius Casca stabbed him on the left shoulder a little above the collar bone, at which he had aimed but missed through nervousness. Caesar sprang up to defend himself against him, and Casca called to his brother, speaking in Greek in his excitement. The latter obeyed him and drove his sword into Caesar's side."