Of that generation, though, I can't help but think that Shamir harmed Israel more than helped it through his inflexibility and belief in the utility of violence. This is to say nothing of the effects his policies had on the Palestinians under his rule. During the 1940's, Shamir was a member of the Stern Gang terrorist group, which sought to achieve a Jewish state through a campaign of assassination of British officials in the region.
In the late 1970's he publicly opposed his own party's peace agreement with Egypt, though after it became a done deal Prime Minister Menachem Begin placed him in charge of implementing it in what I think was a unity gesture. In his longest stint as prime minister, from 1986 until 1992, he responded to the frequently nonviolent and almost always (but admittedly not 100% always) unarmed First Intifada with a violent military crackdown. Under international pressure, he switched from firearms to clubs saying expressly that he wanted Palestinians' bones broken. The First Intifada is considered a turning point in global perception of the conflict, the first time people in the United States in particular saw Israelis as oppressors of an occupied population rather than a small nation under siege from foreign Arab aggression.
With the fall of the Soviet Union, Soviet Jews begin immigrating in large numbers, and Shamir arranged for tons of them to settle in the West Bank. These policies kicked off the 1990's as a decade that would see significant expansion of the settlement project that remains the major obstacle to peace. At the same time, Iraq invaded Kuwait, leading to the first Persian Gulf War. Shamir is often credited with keeping Israel out of that war despite Iraq's missile attacks on the country, but that may be because the first Bush administration refused to give Israel the codes necessary for American pilots to know they weren't enemies.
As part of the diplomacy involved in building the international coalition for that war, President Bush agreed to address the Arab-Israeli conflict. Shamir refused, and Bush earned his anti-Israeli reputation by giving him a hard choice between coming to Madrid to talk to the Palestinians or losing housing loan guarantees needed to economically absorb the Soviet immigrants. Shamir did come with the intention of just putting on a show, but his coalition feel anyway and he lost the elections to Yitzhak Rabin's Labor. Shamir himself left the Likud Party later in the decade when he felt Prime Minister Benjamin Netanyahu was not being hardline enough with the Palestinians, but rejoined after Netanyahu was forced from office in 1999.
Yitzhak Shamir was prime minister longer than anyone except David Ben Gurion, though Netanyahu will overtake him before the end of the year. There is no one, however, whose career better shows that Israel is far from always the benevolent power or that Palestinians are not the only ones who use violence to achieve their nationalist agenda.