Former Alabama Gov. Robert Bentley:

Around 6 p.m. Monday, Gov. Bentley delivered his written resignation.

He will serve one year of probation.

Related: Alabama Gov. Robert Bentley booked into jail, resigns

The Alabama Ethics Commission said last week that they had found reason to believe Bentley committed four felonies in his attempt to cover up an inappropriate relationship with his top aide Rebekah Caldwell Mason.

Here are seven things to know about the 74-year-old Alabama governor:

1. He is the 53rd and current governor of Alabama.

Bentley, a Republican, was first elected in 2010.

2. His second term has been overshadowed by a sex scandal involving a top aide and other ethics complaints.

According to AL.com, when Bentley's wife of 50 years, Dianne Bentley, filed for divorce in 2015, claims that he was having an affair with longtime adviser Rebekah Caldwell Mason surfaced.

In March 2016, a former law enforcement officer who was fired by Bentley filed suit against the governor, claiming his dismissal was a result of his speaking out against Bentley’s inappropriate relationship with Mason.

Just a day later, an audio tape revealing an explicit conversation between Bentley and Mason was released.

He is accused of violating four of Alabama's ethics and campaign finance laws in his attempt to cover up the relationship, AL.com reported.

3. He thrived academically in high school and college.

Bentley graduated top of his class in high school and finished at the University of Alabama with a bachelor of science in chemistry and biology within in three years.

4. He has never accepted a salary as governor.

Bentley promised Alabama voters when he took office that until the state reached full unemployment at 5.2 percent, he would not accept a salary.

At the time of his oath, Alabama’s employment rate was at 9.3 percent. As of January 2017, the employment rate was 6.2 percent, according to the Alabama state labor commissioner.

5. He has a medical degree.

Bentley became a dermatologist shortly after his military service in the U.S. Air Force and, later, opened up his own dermatology practice in Tuscaloosa, Alabama.

6. He was referred to as the “unexpected governor.”

According to the encyclopedia website Ballotpedia, Bentley defeated Bradley Byrne in the 2010 Republican gubernatorial runoff.

“Nobody but the Lord and my oldest granddaughter” expected the win, he said.

7. He endorsed John Kasich for the Republican primary.

"John Kasich is really the only grownup in the room. He is the only one who has a true plan for this country," Bentley said in February 2016, shortly after Donald Trump declined to disclaim former Ku Klux Klan leader David Duke in a CNN interview, AL.com reported.