In the early years of men's Twenty20 International (T20I) cricket, which of the following players held the record for the highest aggregate of runs scored in T20Is?

Introduction / Context:
Run-scoring records in Twenty20 Internationals (T20Is) have changed hands over time as more matches are played and new stars emerge. In the earlier phase of T20I cricket, one of the most explosive New Zealand batsmen, Brendon McCullum, set a benchmark by becoming the leading run scorer in this format. This question tests your awareness of that earlier record-holder, while recognizing that later players may have surpassed his tally.

Given Data / Assumptions:

• The question refers specifically to the early years of men's T20I cricket.
• It asks which player held the record for the highest aggregate of runs in T20Is during that period.
• The options are David Warner, Virat Kohli, Brendon McCullum, and Chris Gayle.
• We assume an understanding that records evolve, but the focus here is on the earlier era of T20I history.

Concept / Approach:
Brendon McCullum was a trailblazer in T20 cricket, both internationally and in domestic leagues. For a significant period, he held the record for the most runs scored in T20 internationals, thanks to his aggressive batting at the top of the order for New Zealand. Although players such as Virat Kohli, Rohit Sharma, and others have since gone on to exceed his aggregate, historically, McCullum's name is strongly associated with that early run-scoring record. Recognizing the timeline and the word “early” in the question is crucial.

Step-by-Step Solution:
Step 1: Recall that Brendon McCullum was one of the earliest T20I superstars, opening the batting for New Zealand and scoring consistently. Step 2: Remember that he was widely reported as the leading T20I run scorer for several years in the initial phase of the format. Step 3: Consider the other options: David Warner and Virat Kohli rose to prominence slightly later in T20I history and did not hold the early record. Step 4: Chris Gayle is a legendary T20 player in franchise cricket, but in T20Is his aggregate was lower than McCullum's during that early period. Step 5: Connect the phrase “early years of T20I cricket” with Brendon McCullum's dominance and select him as the correct answer.

Verification / Alternative check:
If you consult older T20I statistics or articles from around the early-to-mid 2010s, you will find Brendon McCullum mentioned as the leading T20I run scorer at that time. Lists of “all-time leading T20I run scorers” from that period show his name at the top, before subsequent players overtook him. This historical evidence supports the statement that he held the record during the early years of the format, even though more recent records may now belong to other players.

Why Other Options Are Wrong:
David Warner has been a prolific T20 batsman, but he did not hold the early T20I run-scoring record. Virat Kohli has since become one of the highest run scorers in T20Is, but his dominance came later, after McCullum's early lead. Chris Gayle is enormously successful in T20 franchise leagues, such as the IPL, yet in international T20Is his total runs were not sufficient to hold the early all-time record. Thus, none of these players fits the “early years” record description as well as Brendon McCullum.

Common Pitfalls:
A common mistake is to ignore the time frame indicated by phrases like “early years” and instead think only of current records. This leads many candidates to pick Virat Kohli or another modern star. Another pitfall is to confuse T20I statistics with overall T20 runs including franchise leagues, where Chris Gayle and others may dominate. Carefully distinguishing between formats (international vs franchise) and time periods helps you identify Brendon McCullum as the correct historical record-holder.

Final Answer:
The correct answer is Brendon McCullum, who was the leading T20I run scorer in the early phase of men's Twenty20 International cricket before later players surpassed his aggregate.