h1 {
    text-align: center; 
}
h1 span { 
    background-color: green; 
}

h1{
    display:inline;
    background-color:green;
    color:#fff;
}

h1 {
    display: table; /* keep the background color wrapped tight */
    margin: 0px auto 0px auto; /* keep the table centered */
    padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
<h1>The Last Will and Testament of Eric Jones</h1>

.container {
    text-align: center; /* center the child */
}

h1 {
    display: inline-flex; /* keep the background color wrapped tight */
    padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
<div class="container">
  <h1>The Last Will and Testament of Eric Jones</h1>
</div>

.container {
  display: flex;
  justify-content: center; /* center the child */
}
h1 {
    display: flex;
    /* margin: 0 auto; or use auto left/right margin instead of justify-content center */
    padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
    <div class="container">
      <h1>The Last Will and Testament of Eric Jones</h1>
    </div>

.container {
  display: flex;
  justify-content: center; /* centers child */
}
h1 {
    display: block;
    padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
<div class="container">
  <h1>The Last Will and Testament of Eric Jones</h1>
</div>

h1 {
    display: flex; /* set a flex box */
    justify-content: center; /* so you can center the content like this */
}

h1::before {
    content:'The Last Will and Testament of Eric Jones'; /* the content */
    padding: 5px;font-size: 20px;background-color: green;color: #ffffff;
}
<h1></h1> Jones</h1>

.container {
  position: relative; /* required for absolute positioned child */
}
h1 {
  display: inline-block; /* keeps container wrapped tight to content */
  position: absolute; /* to absolutely position element */
  top: 0;
  left: 50%; /* part1 of centering with translateX/Y */
  transform: translateX(-50%); /* part2 of centering with translateX/Y */
  white-space: nowrap; /* text lines will collapse without this */
  padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
  <h1>The Last Will and Testament of Eric Jones</h1>

<h1>  
    <span>The Last Will and Testament of Eric Jones</span>
</h1> 


h1 { text-align: center; }
h1 span { background-color: green; }